I still use it, it's the main reason I don't want to switch to Wayland. Everything looks and feels like it did 15 years ago, it's great!

There are stronger reasons to avoid wayland. It's a protocol that manages to have all implementations slightly different, and creating an EGL context per the glxgears results in a hard crash, both with AMD and NVIDIA cards. I assume I messed up the EGL context, but why does my entire desktop need to crash? Xkill is a much better UX, and that's kinda sad. An Xorg app failing dramatically doesn't murder my desktop session

As a user I also just don't care because X11 satisfies all my needs, and I have never really understood why we needed to change the stack.

https://github.com/waymonad/waymonad (no idea if it's usable)

Not me, because I hate change!

Still on XMonad, what are some good alternatives?

If you want to stay in the land of monads there is https://github.com/SimulaVR/Simula?tab=readme-ov-file "a VR window manager for Linux". Should've been called MetaMonad ;) but I guess that was already taken by the phylum metamonada, don't want to get on their bad side.