Except, family and friends isn't the target here. It's large-ish, professional organizations with a lot more surface area and visibility than your family email server. I've run this kind of friends/family setup, but I've also run a small org setup with a lot more visibility. It's definitely two different beasts... and that was a decade ago.
It depends what. I self host a lot of services for family and friends - but ony the ones I have complete control over.
If there is a problem with something, I want to have a hope of fixing it (either someone already had the issue, or I can open an issue, or I can try try to fix the code/configuration myself). These are great.
Mail not so much. This can become a continuous struggle to get off blacklists, manage spam, troubleshoot deliveries, ... All these are not dependent on me and if I get into a blacklist or if Google stops to accept my mail I am cooked. This is the reason that after self-hosting email for a few years I got back to having it done by people whose job it is .