Volunteering is generally very limited when it comes to for-profit organizations. aside from "work experience" and some "intern" type jobs, taking work for no pay is rare outside of not-for-profit orgs.

Often, Volunteers are on a very temporary basis, usually a day or two, very infrequently. Even interns or work experience programs are time-limited, and an employer either needs to hire that person properly, or let them go when the time runs out.

AFAIK, you can't be a permanent full-time volunteer. I mean, you can just show up and help out if you want, but it would only be of your own volition to do so; and I don't think anyone in their right mind would stick around generating profit for someone else for a protracted period of time, just because they can.

Normalizing that, by not paying disabled workers is not the right move. I think we agree on that. At the same time, we can't really eliminate volunteer jobs. I do a non-trivial amount of volunteering, and there's a good number of things, like fundraisers, that would likely collapse or be very ineffectual if we did away with volunteering entirely.... Fact is, nobody should be given volunteering as their only option for work; especially long-term.