It is dbus api, and is able to work cross-namespaces (i.e. flatpak containers too). There no harm in using it in non-flatpak apps, at least you will be ready if your app ends up in flatpak.
Wrt global shortcuts, I see that there is some work done. The intentional part isn't malice, as in not willing to implement it at all. It is about not implementing temporary solution, that will be quick and dirty, and then being stuck for supporting it for next 50 years.
It took Golang 12 years to attain generics. Wayland is already 14 years old.
To tell the truth, X11 took roughly 10 years (1986 to 1996) to get to a pretty usable, while pretty imperfect, state, and largely dominate Unix desktops.
Wrt global shortcuts, I see that there is some work done. The intentional part isn't malice, as in not willing to implement it at all. It is about not implementing temporary solution, that will be quick and dirty, and then being stuck for supporting it for next 50 years.