Element X does video calls fine. It's been ages since it was the messy beta you describe it as. In fact, it does calls better these days. There's no good reason to go with Element Classic anymore, I don't understand why they don't just drop the old thing.

All the other things are just as true if you replace "Matrix" and "Element" with "email" and "outlook"/"gmail".

If you don't think the person you're talking to understands the difference between apps and emails ("I can email outlook people from my gmail?" is a serious question these days), just don't mention it. They're not going to get into the weeds anyway.

When I tried to explain the different "servers" in Discord to some a-technical people I had the same problem and disabling invites + not bothering with explaining the server concept seems to work out a lot better. I've given up trying to explain computer things to people who don't want to understand how the things they rely on work.