kde-plasma/plasma-meta unconditionally installs kde-plasma/kwayland-integration which pulls in wayland. Please put that behind the wayland useflag to make it optional. I'm not ready to play with wayland yet, so I don't see a reason to have it on my box. I could install everything plasma-meta installs except for wayland, but I'd rather use the meta package to keep my @world set cleaner.
Various other Plasma 5 packages use libwayland unconditionally, even on X.
$ equery d kwayland * These packages depend on kwayland: kde-misc/kdeconnect-9999 (wayland ? >=kde-frameworks/kwayland-5.21.0:5) kde-plasma/kinfocenter-5.6.4 (wayland ? >=kde-frameworks/kwayland-5.20.0:5) kde-plasma/kscreenlocker-5.6.4 (>=kde-frameworks/kwayland-5.21.0:5) kde-plasma/kwayland-integration-5.6.4 (>=kde-frameworks/kwayland-5.21.0:5) kde-plasma/kwin-5.6.4 (>=kde-frameworks/kwayland-5.21.0:5) kde-plasma/libkscreen-5.6.4 (>=kde-frameworks/kwayland-5.21.0:5) kde-plasma/plasma-integration-5.6.4 (>=kde-frameworks/kwayland-5.21.0:5) kde-plasma/plasma-workspace-5.6.4 (>=kde-frameworks/kwayland-5.20.0:5) kde-plasma/powerdevil-5.6.4 (>=kde-frameworks/kwayland-5.21.0:5)
This thread is relevant and indicates that KDE unconditionally requires wayland: https://forums.gentoo.org/viewtopic-t-1045534.html If KDE really can't be separated from wayland, then could a note of some kind be added to the wiki explaining why? Thanks!
We can't fix this as this is an upstream decision.