A alternative way to increase a Pokemon game's difficulty in future games

Please provide some feedback, I'd love to hear any additions. Please try to read most of it before commenting, I tried to cover most counter-arguments already.
Usually a heated source of debate for Pokémon fans is the difficulty of the games and how to make it more challenging. With the release of Let's Go coming out soon and a new main series game coming out later on, I've noticed a lot of people fearing alienation from the series in regards to not just mechanics, but to how much of a challenge is going to be presented. 
Obviously we would want to accommodate for all fans; those that want the hardcore, gruelling challenge, those that want a relaxed, heartwarming adventure and those that want a perfect in between. When someone wants more of a challenge with Pokémon, a nuzlocke run is usually the most applicable solution and I see a lot of people recommending nuzlockes to people who complain about breezing through the game with little thought. I also see some people wanting it as a base feature on the game but I personally find that nuzlockes have some shortcomings and aren't a great way of presenting challenge.
First off, nuzlocke runs are entirely self-enforced. While it could be argued that this doesn't entirely make a difference, this makes the runs easier to exploit and overall not enjoyable to some. Players can grind until the threat of an opponent's Pokémon is nullified and the challenge is removed. Alongside this, some people like myself just don't enjoy self-enforced rules. They feel inhibiting and I've sometimes caught myself out on not realising a Pokémon has fainted and continued using it without realising. While it could be seen as a minor issue, it should preferably still be avoided.
A second issue with nuzlockes is that they don't utilise a core component of what can make a Pokémon game challenging and that is the strategy of trying to outplay an opponent. The AI battles are usually very easy to exploit and read, using nonsensical moves and switches that have no effect on the outcome at all except to sometimes even screw themselves over. Difficulty should test the knowledge of battle, not just to avoid getting hit by miscellaneous critical hits.
While having nuzlocke as a base game difficulty could help alleviate some of the issues, it doesn't help with the latter points or some other bad situations such as the rare case of getting a shiny or accidentally losing a highly trained Pokémon forever while fighting NPCs. This is where I would like to provide a solution to this that would hopefully help fix this issue, while also maintaining a casual experience for those that may not like Let's Go, but still want to play the core games. 
Firstly, the game should give the player an option on character creation to select a normal or hard difficulty. The normal mode would be the typically fashioned game of Pokémon and would allow all the usual features that would be in a core series game. The hard difficulty however, would offer a greater challenge by pitting higher leveled Pokémon against the player, an experience/level cap on your Pokémon, a smarter and more diverse AI to battle against as well as other minor features. 
An obvious limitation to this would be that a player could still cheese the game by going back and forth to a Pokémon centre. My solution to this would be to block off the escape to a town once the player has entered the route and make it available to explore properly once the player has made it to the other end, with trainers only becoming defeated upon making it to the next town. This would allow for a more careful and tactical approach to team building, where tanks and walls may be favoured over button mashing super effective moves. Items and money would become useful and invaluable instead of redundant, since they would need to be used resourcefully to ensure the route is passed. This would be a good way to make use of the resources the game has given to the player and creates new strategies and challenge within the exploration of routes. It also means the game doesn't become too overbearing with losing Pokémon and can maintain pressure while allowing players to feel at ease at not having lost the game entirely.
To make the game flow better, experience and leveling should also be reworked to make use of the full potential of the amount of levels available. Most Pokémon games end with the player's team only reaching 50-70, which isn't that high considering they can reach 100. Much to the bane of the more competitive and thorough players, Sun and Moon was especially bad to grind up to level 100 with and while this is annoying for those who need moves from later levels, it also made the new and useful hyper training a generally huge waste of time.
For Pokémon to maintain difficulty and to allow further flexibility for trainers, a level cap could be given before and after every gym with a Pokémon not being able to go beyond a certain experience threshold until the gym is defeated and the level cap changed. This would completely remove leveling cheese and would allow for more fair gym battles that can be focused more heavily on the actual strategy of the fight rather than the levels that each Pokémon has. For traded Pokémon, a 'true' experience gauge that can't be altered could be introduced as to not upset the campaign leveling. This would allow the Pokémon to retain its original level but function as a level capped Pokémon during the campaign. Once the player gains the required badge to see the Pokémon's level, the experience gauge would function as normal.
My next proposition would be to remove IVs and seperate hidden powers into a random value for each type. This would still help Pokémon retain some original flair, would allow access to Fairy hidden power and would remove the desire to use action replays in VGC format. IVs were used in the past to make certain trainers harder as well as add some individuality to a Pokémon. By fully utilising levels and level caps more, they could easily tweak certain Pokémon to be higher level and therefore a larger threat. EVs as well as hidden powers would remain to give a Pokémon a unique flair and further customisability between sets just like it always has. The biggest to benefit from this would be the competitive players. If this were to happen, soft resetting for high IV legendaries, breeding for hidden power IVs and chaining dittos, all the heavily RNG reliant factors would not be a problem any more.
However, smarter AI would be necessary to make full use of the changes. While playing Pokémon, most battles from start to finish are just making use of super effective moves to quickly finish off the opponent. Now that gyms and other trainers would be on a level playing field, it would now have the potential to test the player. Trial battles were a good way of showcasing what even some simple design can do to amplify the difficulty. While not the most challenging thing possible, trials showed that trainers needed to be prepared or risk getting swept by the totem. Simple changes to formula such as giving gym Pokémon items, coverage moves or even making them double battles would significantly help along with an AI that is able to punish mistakes. With higher levels, better AI and extra utility, gyms could be feared again just like the dreaded Goldenrod gym with Whitney instead of pushovers like the Coumarine gym with Ramos.
With these additions, post-game activities could be freed up. With highly trained Pokémon, more options open up for further battles and challenges. For those that liked trials in place of gyms, trials could be re-included as hidden side missions on each route that provide an extra layer of difficulty. With high level Pokémon, trials of each type could be unique and challenging. Imagine an attack boosted, earthquake Garchomp being fed sandstorms and health from a support Pokémon, or a special attack boosted, trickroom supported Reuniclus in psychic terrain. The possibilities for end game trials could be fun, challenging and fresh from all the unchallenging and empty post game content of the last few games.
Naturally, this would be a huge overhaul in mechanics and may feel jarring to those that love the current working of the game but by giving the player options to select the way they want to play, it gives even more pathways than before for all fans to enjoy. Would you rather a game like this or not?