Keyboard-only access is an important part of accessibility. In my case, it's simply because my mouse has stopped working, but there are many people who rely on webpages being keyboard-only friendly to navigate the web.
Stack Exchange chat completely fails.
Some extremely basic things are impossible to do without a mouse. Here's a list of some things I ran into:
- replying to messages
- flagging a message
- finding a specific message's transcript link
- starring messages
- kicking users
- adding room owners
- dismissing pings
- dismissing notification bar - such as a "<user> has been kicked from <room> by <user>" notification
- clearing stars
- loading older messages
In search, removing the "said by user" or "said in room" is impossible. Clicking the "show more" for stars is also impossible to get at.
This all serves to make chat very inaccessible to keyboard-only users.