Example 1: Reddit is on GitHub. At the time when I was still using Reddit, I was pretty pissed with its lack of helpful accessibility. So I went on GitHub, and wrote a PR which would wrap individual articles on a page in a so-called "region" so that the screen reader could easily jump to the next article. The PR was ignored for several months. After a while, I simply closed it out of frustration.
Example 2: When I read about Bitwarden on HN, I tried it. As I am an iPhone user, the iOS app was interesting, so I installed and tested it. No surprise, almonst no button was labeled correctly, or labeled at all. So I opened an issue on GitHub. The answer I got was: "Yes, we know we are not accessible, but we are planning a rewrite anyway, so we will not change anything in the existing code". Thanks for nothing. We are not talking about rocket science here, just adding a text label to a handful of buttons. But yes, thanks, I got the message. Nobody really cares about people with disabilities.