I don't think that would help blind users.

In before Steam has moved off of web interfaces (I haven't checked in a couple of years so they might be doing something different now particularly with big picture mode), but I'm frustrated that we all started building interfaces for native platforms in HTML/Javascript and it didn't lead to embracing any of the accessibility features that those same interfaces would get by default inside of a web browser.

To be fair, my understanding is that Linux screenreader support is pretty bad, but it does seem like if a developer is going to the trouble to build the majority of their interface in a semantic XML-like pure-text format, there should probably also be an option to read that text out loud.

Part of Steam is indeed HTML, and that is the accessible part. They're rewriting more and more of their UI in that technology, and that's definitely a good accessibility move.