flexibilty allows your teammates to play on there best play styles on there best roles it cannot be overrated imo making your entire team instantly better via your agent pool can never be a bad thing and having a player who can perform in any meta on any agent cannot be overrated
forsaken and prx in general proved that look at there placements across YEARS look at there placements 2nd-4th place avg is INSANE
look at how many teams have fallen off optic fpx loud to a certain degree and there still placing saying a player is overrated because they can play EVERY ROLE IN THE GAME on any agent is crazy
i do agree that teams who win have mostly stable roles but you need a good flex to win and good flex cannot be a bad thing because riot loves to make random changes before major tourneys