It seems that only "general purpose" room associated with Ethereum which isn't frozen is the election chatroom: chat.stackexchange.com/…

And people are using it basically as the "main chatroom" for this site. (Although the activity is rather low.)

Perhaps it would make sense to unfreeze the room which was originally intended as the main chatroom?

Although it was frozen for rather long time:

I have mentioned several instances where the only room associated with some site is the election chatroom here: chat.stackexchange.com/transcript/130426/2021/12/4

Unfreezing done @MartinSleziak but I don't know the Ethereum folks well enough to politely shut them over to the main chatroom

@JourneymanGeek Thanks for unfreezing that room. (We'll see to which extent it is going to be used.)

For matrix.org, there is a beta "Spaces" feature/aspect, which somewhat (relatively...) topologically organizes, say, "Bitcoin" er "Ethereum" rooms into a "Crypto" chat category, helping User Discovery theoretically. (I think it took me some years to notice, that Quora attached additional charges to what I was moderated for, several years after the fact. I was told "style issues" and that changed into major crimes for, I'm guessing, editing Quora Topics. I edited topics for yrs/mnths then boom.)