> having to maintain both X11 and Wayland support forever everywhere
I don't get why X11 shouldn't work forever. It works today. As you said, there's no obvious reason for an end user to switch to Wayland if there isn't any particular problems with their current setup. "Because it's modern" and "Because it's outdated" just aren't compelling reasons for anyone besides software developers. And "because we're going to drop support so you have to switch eventually" is an attitude I'd expect out of Apple, not Linux distributions.
I don't get why X11 shouldn't work forever. It works today. As you said, there's no obvious reason for an end user to switch to Wayland if there isn't any particular problems with their current setup. "Because it's modern" and "Because it's outdated" just aren't compelling reasons for anyone besides software developers. And "because we're going to drop support so you have to switch eventually" is an attitude I'd expect out of Apple, not Linux distributions.