I’ve learned to like systemd over time, but not snaps and how Canonical handles things.
Debian also uses systemd nowadays, maybe you can try devuan (I think that’s how it’s called,) which is debian based but without systemd. I only tried it once on a server but came back to debian.
What could be possible, would be maybe send tiny bits. For example, a device could categorize some places or times, detect out of pattern behaviours and just record a couple of seconds here and there, then send it to the server when requesting something else to avoid being suspicious. Or just pretend it’s a “false positive” or whatever and say “sorry, I didn’t get that.”
I don’t think they’re listening to everything, but they could technically get something if they wanted to target you.