TL;DR: Is my statement below incorrect? Are there in fact meaningful efforts to improve accessibility on Linux? Are there distros that people have actually used practically that make an effort to be accessible?
I have used desktop Linux on and off since 2009, mostly flavors of Ubuntu with occasional detours into things like Arch or CentOS (RIP).
I currently have Mint installed on a separate drive but I can't fully break away from Windows because as a blind user the experience is not only unsatisfactory it has gotten worse in the years I've been using it. Orca hasn't improved at all, and the magnifier has actually lost functionality at some point, my guess is the move away from GNOME 2. Among other things you used to be able to assign arbitrary modifier keys to zoom in and out with the mouse wheel but this is no longer the case.
I have little faith that things will improve. Any given Linux distro isn't one product, it's a bunch of different projects. One group makes the kernel, another makes the shell, another the window manager, yet another makes the desktop environment, audio, bluetooth, graphics drivers etc. All these make the assumption that the user is able-bodied, and bolting accessibility on top of all these disparate systems after the fact is very difficult. It's no accident that MacOS and iOS are frequently cited as the most accessible platforms. Apple controls the entire stack from hardware to UI and even many of the apps and has the resources to devote to serving a comparatively tiny portion of their userbase.
While that's probably true, I think it's understandable how one can see such a vague, incomplete response as being unhelpful. It just seems so pointless to me to not even give a minimal explanation of why you think it might help - which wasn't done until I complained to that effect.