@Daze623 They have said his winrate hasn't really changed.
I'm not sure what my example and whether it was pubs or ranked has to do with anything. It was just my only example where I saw a difference. It was actually a better example than what you showed as the person should have died.
I don't play ranked much and when I do I play it like pubs. I'm not a fan of grinding for points if teammates die or watching teammates if I die.
I do have a friend who mains caustic in ranked. He made it to diamond pre and post nerf and said he hasn't noticed any difference. He is an aggressive player and does it solo queueing.
So we have you, who admitted you do not play caustic, saying he is useless now and many of us who play caustic saying they do not notice a difference.