General Overview: /tts as it is sucks for those who actually need to use it and this shouldn't be their only option
Suggested Changes: (1) have a text option within voice channels that doesn't save text but reads aloud with a green ring (just the same as anybody else talking) this can be turned on or off for channels or given as a permission by an admin to those who need it. Also a small user side overlay so they can type in voice without having to minimise the game being played
(2) have an option so people can click on written text and hear it spoken aloud (user end only)
Bit of a rant: Text to speech really needs work. I have seen a few able bodied people complain about it but here I'm only going to complain about it from an accessibility point of view. The fact you can only turn it on from either the text channel you are looking at, or all text channels at once is pitiful. As you either have to be in the exact same channel as someone at the exact right time as someone to hear them or hear everything typed by everyone across every server simultaneously. Which drowns out the people actually needing to use it. The point of /tts is first and foremost to allow people unable to talk the ability to join in a voice chat. Why on earth is there not an option for tts within a voice channel itself? This doesn't need to save the text, and could be turned on for individuals who need it by an admin of as server to stop spam, but means your voice (through tts) is actually heard as part of the conversation as if it was spoken just like anyone else. Also they if playing full screen on one monitor (which lets face it is most of us) will have to either minimise the game or use an overlay that covers almost the entire screen just to be heard.
The other use that people may actually need text to speech for is also another way we are currently unable to use it for. For people with limited vision why is there not an option to click on text and just hear it your end? nobody else would have to hear it but would help them massively with being able to join in with written conversation.