I honestly just stick with X11 because of the high degree of compatibility, and I often already rely on X11-only software anyways like Redshift (I know there’s Wayland-supporting alternatives, but I’m picky and don’t like switching if I don’t feel I need to), also my DE/WM of choice is currently awesomewm and I think I’ve heard mixed things about using awesomewm on Wayland (or it might not even be compatible at all. I just woke up and I’m struggling to remember lol)
Even without considering laptops, I can already imagine quite a few circumstances where someone might want monitors of differing DPIs. I’ve actually thought sometimes of getting a smaller monitor I can have off to the side that I display a browser window containing mostly text on when I’m playing videogames or working in something like Blender or Aseprite; yknow, for referencing a guide, wiki, or manual or something. I don’t even have a super high desire for a multi-monitor setup outside of that.