Is S2 Chun-Li THAT bad that literally just nobody uses her?
useage isn't just affected by tier, the character design itself also led to her not being that popular even when she was considered top tier. To expand on that, she is extremely hard to play - her projectile is a charge, insta air Legs are a core part of her game, and her BnB is one of the hardest combos in the game. Then, adding to that, her max damage combos she has to work EXREMELY hard for, with combos being up to 50 hits or more (many multi hitting moves, but many inputs per a combo, plenty even longer than Bison's biggest combos), with at least one and sometimes more tricky links per a combo, and after her season 2 damage nerf, the final result is still pretty meh damage, often even less than some characters regular BnBs for spending VTrigger / meter. So basically she isn't really rewarded for the work you have to put in with her now.
Whether or not she is the absolute bottom, she is definitely at the very least low tier character, so this combined with her design makes her usage completely unsurprising to me that she is the least played.
However, she ALSO has the lowest win rate in the top 100, which is a completely different statistic to play rate (as shown by someone like FANG who while heavily underplayed, still has a mid tier winrate in top 100), and at that level it's only the high execution / quality Chun's left, so the fact that even they can't compete definitely suggests that she's in need of a proper look that isn't just season 1 salt. A lot of people jumped ship after the first round of changes, that doesn't mean anything people will always flock to high tiers instead and ones who get nerfed below that, however even Chun loyalists are throwing in the towel everywhere, her community is pretty unimpressed with her, and a lot of people who never see her because of her usage and don't play her and don't really know anything about her current state push this "shes fine, still very strong, etc" narrative mainly based off their theory about how strong she was in season 1 and how the nerfs couldn't have hit her that bad. As I said, I'm completely unsurprised by her win rate and I expected her to be bottom 3 maximum in success.
I don't know whether or not she was the worst character when you made this post, but now with nobody getting nerfed down to her level, everyone else at her level getting buffed, and her just getting more nerfs, I'd say she is almost guaranteed the worst character in the game now, and that win rate defecit that she already has against literally every character is going to grow even larger, and I know her useage is going to drop even further as there was a whole lot of Chun mains who have said they were waiting out for this patch with their fingers crossed before finally dropping her. Based off those patch notes, safe to say they won't be sticking with her either.