As far as I know, the protocol is pretty much standardised and it's now up to the desktop environments to support and implement it, and that transition took a lot of time. GNOME has already been there and on its way to winding down X11 support, KDE has also been building up its Wayland support too. Waydroid (Android container software) requires it, and Valve uses it for Gamescope on SteamOS too iirc, to give games a more predictable place to render themselves on. Everyone's got a kick up the ass with regards to Wayland support recently, but for smaller, independent/non-corp backed or niche software, of course, it's gonna take a bit longer.

It's kinda like IPv6.

More than it being half baked, it's that is not a drop in replacement. It works differently, on purpose. So DEs, apps and even drivers (looking at you Nvidia) need to make changes to adapt to it.

For example apps that user screen sharing had to be reworked, because X11 allowed any app to just see the screen without any user action (I think Windows also does this, Android and iOS require at least a one time permission), but Wayland doesn't allow that as it's a security/privacy risk.