It sucks because going after UGC was my number one strategy. All hope isn't lost though, at least not yet. Build a list of your weak competitors. Plug them into SemRush or Ahrefs and steal all of their top ranking keywords. This way you know a blog/website is rankable for these keywords. The problem with SEO right now is that it is in a transition phase and we don't really know where the dust will settle. Things are in a limbo for now until Google adjusts their algorithm to combat AI (if this is ever going to happen). It is entirely possible that the future for search is all about constant algorithm changes, in that case you will have to keep adapting. I would advise looking into alternate traffic sources, we don't really know where search is going for now.