The entire high elo flex ladder is filled with people abusing smurf boosting and nothing is being done about it.

Seriously look at the entire challenger leaderboard for flex. Almost every single challenger player's match history is filled with games with 1 challenger and 4 emerald new accounts playing together so they play against low elo enemies and secure free wins. They also blatantly share accounts with each other. The worst part is that Riot recently announced that they are going to ban people in Valorant for doing the same thing, but League Flex Queue is usually ignored because not a ton of people play it. The same rules for Val need to be implemented to flex to prevent people from reverse boosting their friends top the top spots.