Wayland itself has lots of missing features. There are applications that need absolute window positioning to move sub-windows together with the main window. It’s not an issue on Windows, Mac, or X11, but Wayland doesn’t have a protocol that would allow this (it’s still just a proposal, and there is A LOT of drama surrounding it). Wayland also doesn’t have color management, and support for drawing tablets is rudimentary, which is a deal-breaker for artists and designers. It doesn’t have a standardized way to capture windows either (for streaming or recording), which is why Hyprland’s maintainer made his own xdg-desktop-portal implementation with blackjack and hookers.
Wayland is great for my use-cases, and I’m willing to work around its issues (mainly related to portals), but there are use-cases where it’s completely unusable. Nvidia support is also sketchy - lots of visual artifacts and flickering windows.