The end of the game is a huge slog

Bannerlord is a ton of fun during the journey, but late game it sort of turns on you.

It's not that I don't enjoy a good siege, it's that every single one of them is so stupidly stacked against the attacker, regardless of what tactics you employ, that it's ridiculous unfair, and while sieges will be a once in a while thing for a long time into the game, past a certain point they will be all you are doing.

I found an interesting thing recently. When you are in a siege (possibly just in general as well), you can join with 150 troops, and they will not reinforce until you are at 30 troops, and then only back to 90 troops. that means even a garrison a tiny fraction of your army size will have a numbers advantage in a siege, on top of the normal advantages fortifications offer. The way archers take cover under the rough cover leaves them fractionally effective, if you just leave a siege on the normal advance after starting, you'll take ridiculously disproportionate losses even though you'll likely have better troops than them. The ram is like a joke, if you bust down the gate even superior troops will start to fall as the enemy instantly reinforces (which is fine, it is their castle), while your troops wait until the squad is 4/5ths dead for a new blob to appear, who won't be in position by the time the other 1/5th is completely overwhelmed.

The only way to take a castle without ridiculous losses is to line up your archers in the open in loose formation and use archer superiority to whittle them down while your infantry and cavalry sit behind their shields soaking arrows. Specific tactical moves can work, like moving up to the walls yourself so you can give an infantry unit orders to position in a likely spot to clear enough room for archers to take to their walls, in fact that's very effective, but usually the second you have infantry on the wall their entire force will descend on them until they are forced off or the enemy is completely out of reinforcements, meaning by the time you have them inside it's already over. That's assuming you are advanced enough with heavy enough armor to tank through a horde of enemies in order to give the order for your troops to move, since on attack or advance they turn into complete idiots.

Sieges need a ton of work, but also the diplomacy game. Once a faction has no land, they keep respawning in yours, with free troops. There's no way to end it, and even if they want peace you shouldn't, because the only way they cease to be a problem is when the lack of ability to reinforce or sell their stolen goods results in them being too small to successfully overtake even a village militia. I'd say if you come across a defeat kingdoms lord, beat them down and retreat in the final moments, leaving them with nothing to continue being a thorn in your side. This could almost be called a solution, if it weren't for the fact they'll magically pull mercenary hiring funds out of their ass once in a while and some random mercenary company will cut a swathe through your villages for a while.

Everything about the endgame is fucking infuriating, and it's already infuriating the cheaty degree to which AI are just given massive free resources the more you are beating them down. I have no idea why the game is designed in such a way that no matter how frequently and thoroughly you are winning, the enemies are going to be non-plussed and just hulk up with another 500 man army even though they have 3 castles and no towns between all 12 of their fucking clans. It's utterly ridiculous the degree to which the game establishes complicated rules of engagement and then only applies them to you specifically. It's worse when it descends from a real threat to a constant, unending annoyance that there's no recourse to defeat.