I think there are a couple of main recurring issues.

First and foremost: X11 is mostly OS-neutral and portable, while everything Wayland was designed by the freedesktop people with their ecosystem in mind. ie: assumptions that Of Course dbus, policykit,consolekit2,systemd,etc are all there and set things up properly so Wayland stuff doesn't need to. In their world, it's a bug if wayland stuff doesn't fully use/rely on all those things. We've shunned that stuff where possible but there's a cost - we have to reinvent/reimplement stuff that the native implementations don't need to even think about.

Second: People willing to try it suffer a thousand paper cuts and get worn down quickly. There's not a huge amount of community knowledge about it on our side because many people who try .. get burned.. and swear off it. If anything, the community knowledge is trending towards It Doesn't Work/It Cannot Work/It Isn't Worth Trying/Wait Until Somebody Else Figures It Out. But there are some brave souls that do persist and get it working - there are huge threads on the forums where the survivors gather.

Third: a lot of this doesn't Just Work out of the box on Linux either. If you look under the covers you find that there's often kludges/workarounds/fork-another-distro's-custom-configs going on.

Fourth: There is one Xorg server but there are MANY waylands. I think a web server analogy is appropriate. Yes, they all speak HTTP but Apache/nginx/tomcat/caddy/etc/etc are drastically different when you get below the surface. How you launch/manage/configure/integrate them is as varied as the wayland implementations are.

Wayland works on FreeBSD. It's more a question of which implementations? It is also more of a challenge if you're trying to use them as an integrated system rather than piecemeal. Finding the right clue in 250+ page long forum threads can be an ordeal.

Hint: the public LLM chatbots seem to have ingested many of these forum mega-threads and can likely find breadcrumb clues quicker than you can with a search engine.