It’s a fair point. Like Nick says in the video, if Linux becomes more mainstream it will likely be a long-term thing and not all at once. In that sense, if it gradually grows, there could be more focus on accessibility and that could boost it.
Mark Brown has a series on YouTube about accessibility in video games, and I believe in his last big review he talked about how games have successfully moved from bad accessibility to much better. That’s due to awareness. If there can be a similar movement within the Linux community or at least some projects. It’s not like folks are actively against this kind of thing, in my opinion.
If anything, I feel like accessibility kind of dovetails with the ramped up customization that comes with Linux. But it’s easy for me to say as a noob with little technical experience.