A lot of X features are actually Xorg features and they only work because there is a single implementation that everyone tried to integrate with.
Turns out the moment there are two implementations, which is hard on X and easy on Wayland, you can no longer rely on targeting a single implementation for direct integration anymore.
This means a lot of non-X but Xorg features need a protocol extension in Wayland, because things are being standardized that previously were exclusive to Xorg.
Are you saying that you can't get the title of the active window in X11 without using some features specific to the X.Org implementation?
It looks like the core X11 protocol spec [1] defines all that's needed, specifically the GetInputFocus, QueryTree and GetProperty messages. You might also want some things from the EWMH spec [2] (e.g. _NET_WM_NAME for UTF-8 or _NET_WM_WINDOW_TYPE to identify top-level application windows) but none of this seems like an implementation-specific X.Org feature.
Read this including my response.
A lot of X features are actually Xorg features and they only work because there is a single implementation that everyone tried to integrate with.
Turns out the moment there are two implementations, which is hard on X and easy on Wayland, you can no longer rely on targeting a single implementation for direct integration anymore.
This means a lot of non-X but Xorg features need a protocol extension in Wayland, because things are being standardized that previously were exclusive to Xorg.