The parallel is that email is built on a standard (well, two; RFC-5321 and RFC-5322), and it doesn’t matter what email server you use, whether it’s Gmail or Hotmail or a box in your basement running postfix, they’re all supposed to follow the standard and talk to each other; that is, they form a federated network. In the fediverse, we mostly use the ActivityPub standard, but the idea is the same.
XMPP is probably a technically better comparison, but try making that comparison to your parents. The point of the email comparison, even if it’s slightly less technically accurate, is that people have actually heard of email
I’m actually in the middle of deciding on a new distro, I’m trying to get away from Ubuntu/snap, but Debian 12 with LxQt or Xfce isn’t playing nice with my laptop. I just finished writing out Mint and Tumbleweed flash drives, gonna give them both a shot, but I’ve never really used openSUSE before.
There were, I had every odd Samsung flagship phone since the S3, and two of them (S5 and S7 or S7 and S9) were waterproof with removable backs to change the battery (and SD card)