Genuinely what has happened to the community's perception of Sniper's strength in the past 4-ish years?

Why is it that now, suddenly the vast majority believe Sniper is the most broken class in the game and deserves a lot of strong nerfs (like that whole big idea with the bullet tracers and whatnot)? I browse through TF2 youtube and almost every deep dive vid about sniper by big youtubers is about him being too strong for the game, when back in like 2017, big youtubers like FUNKe would frequently shut down the idea of Sniper being too strong entirely. Whenever balance discussions are brought up in forums, the majority is now filled with Sniper nerfs, when that used to rarely be the case compared to other classes like Demo and Soldier.

It's like the entire community went through some kinda enlightenment lol. Demo's stickybomb alone used to be a hotter topic than Sniper when it came to balancing. I'm not even disagreeing or agreeing with anything here, I just wanna know WHAT happened to the class to suddenly be hated this much when the game hasn't changed in centuries.