Are you willing to write accessibility support for the new xfce only wayland compositor? How will you get every other wayland compositor to support your non-'wayland core' accessibility extension?
People like to frame things like the waylands are some sort of default and nothing is being lost and no one is being excluded.
Everyone has settled on an accessibility standard (Matt Campbell's). So it's not "your" accessibility protocol, it's already "the" accessibility protocol. This is working as intended IMO: allow things to compete and future in the wild and then pick the fittest.
People like to frame things like the waylands are some sort of default and nothing is being lost and no one is being excluded.