We’ve stuck with fire tablets forever, they can install the Google Play store and the kids tablets still receive updates a few years later. The newest ones have USB-C, headphone jack, good enough WiFi for us 2.4 and 5GHz, and can be picked up under $100. The 8" version is really good and they have a 10" version as well. I know fire os isn’t amazing and gets a ton of flack but it works for what it’s designed to do.
I’ve looked at revolt and well, when I tried using it it was filled with less than reputable individuals. I don’t remember specifics but I remember noping the fuck off revolt real quick. If you want text chat, try matrix, if you want voice well, then idk what to say other than discord, team speak or guilded. Guilded is pretty cool, I actually like the client way better than discord but my friends all use discord and guilded isn’t a huge platform. It is backed by the Roblox company so you at least know it’s gonna be supported, but then again, it’s the Roblox company…