Your post is being ignorant of the situation though.
Remember when toplaners were irrelevant because they couldn't carry games and tanks dominated. Assassins also felt like they were never able to get through shields either. They felt like there was so much CC as well that they'd get fucked over. They complained there were ADCs in top and mid despite them having a 45% winrate in those roles and being detrimental for the game. (Vayne top is a low elo meme, Jhin mid is garbage, and Lucian mid is because Riot always overbuffs him, while Ezreal is an abuse case every single season in all lanes)
They nerfed ADCs and supports while buffing toplaners and assassins because of all the complaints of how much their classes were unviable. Now the tables are turned. Over 80% of the ADC roster is useless and supports with shields or heals are garbage because they can't engage, disengage, do burst/damage, or keep their team alive. Supports poking/engaging are now the sole answer. Not the shield/healing/protective part of their kits.
For the first time in many years, you don't know what to expect in matches. Games aren't always just carbon copies of one another and super stale.
You're saying that about League - a game designed to literally be a copy of the same map, always have meta champions every year, where you do the same thing every time. Only difference is the damage, fun, and ways you can now play it. Before you could either scale, stomp early, or macroplay your way through the game. Now it's damage over damage.
People aren't complaining about diversity. They're complaining about their entire class getting fucked over.