I would assume that there usually isn't an immediate economic benefit of doing so. Fortunately, we live in a society that is much more inclusive than it used to be. As Tim Cook said, "When we work on making our devices accessible by the blind, I don't consider the bloody ROI".
Aside from the monetary benefits (or lack thereof), if one product focuses on accessibility and another doesn't, the small subset of users who need those features may encourage or force a larger number of users to use the more accessible product. So long-term, I think there is a benefit, even aside from helping make society more inclusive.
This sort of commentary betrays a stiflingly first-order thought process.
Sure, being "more inclusive" is a benefit - this is included in any utilitarian or economic analysis of the change. However, instead of spending X marginal dollars being more inclusive to deaf people, you could also spend that money on any number of other outcomes (pick your pleasant-sounding cause: cancer research, homeless outreach, just making everyday people's lives a bit better).
If you don't understand how "monetary benefits" tie in to scalable social optimization, you should probably not offer opinions on which causes people (and companies) should put money into.
Also, keep in mind that you have ~zero skin in the game here, and Zoom has a lot, so you should lend a lot of credence to what they choose to do.
One day, you might be. Just be glad you won't be left behind.
Edit: If you want a purely numbers based analysis, well, you're not considering second-order effects. Investment in accessibility represents an investment in technology. ASR in meetings, for example, is a necessary first step towards good auto-translation.
This is the exact stupid response I mentioned earlier: “be glad you’re not disabled!” How about you get a real argument instead of just shaming people?
Aside from the monetary benefits (or lack thereof), if one product focuses on accessibility and another doesn't, the small subset of users who need those features may encourage or force a larger number of users to use the more accessible product. So long-term, I think there is a benefit, even aside from helping make society more inclusive.