A11y support vendors are _not_ paid by the people who utilize their offerings, but,instead, are paid by third parties. Those third parties are either government agencies, or non-profits. In either instance, they need to justify having a higher budget each year. Even when the FLOSS product outperforms the commercial offering, the commercial product will be utilized, because that does not threaten their revenue stream, whereas the FLOSS product does.
IOW, under the current a11y ecology, it doesn't matter what FLOSS solutions are presented, because the organizations that allegedly help those who have a11y issues, get more revenue from rejecting FLOSS, than embracing it