Might just be me but I feel if something has been requested for 5 years it might be time to look into it. I love home assistant and I am in no way a programmer. (then I’d just do it myself for the community). The ability to connect and use voice asistant with the Android TV os would be great though.
The thing is, they spent those years building out the voice assistant support. That was probably a better use of their time than reworking the entire interface to work with a TV remote, in my opinion.
They are a small team with a lot of help from the community. You can’t tell the community what to do since they volunteer their time, and the small team has a focused road map that I think makes sense.
I bet you could find another 100 examples of things not done for 5 years, it’s just this is the one you in particular want.