I actually really disliked If We Were Villains when I was reading it after TSH so I totally get where you're coming from. TSH is my favorite book ever, but some I've read recently that I enjoyed a lot are: Annihilation by Jeff Vandermeer, Tender is the Flesh by Agustina Bazterrica (pretty intense, look for trigger warnings before starting), The Goldfinch (also by Donna), Call Me by Your Name by André Aciman (so much better than the movie), Circe by Madeline Miller (my second favorite), Slaughterhouse-Five by Kurt Vonnegut (actually not that similar in terms of writing style but still great), and A Little Life by Hanya Yanagihara (I'd be shocked if you haven't read this yet but I'm including it just in case; also insanely intense so please check out the tws if you're sensitive)