I'm working on same for my family since I want to properly degoogle a bit. One thing I think long term - if I give my kids first-name @ last name , that means that I forever hold power over their email. Which isn't great. But what's the alternative? Register one full domain name per kid? Even ignoring the cost, the ergonomics are awful.

Imho email is missing a feature for nameless email addresses for when somebody just buys their full name as a domain name. If I get "firstname-lastname.name", having the email be "[email protected]' kinda ruins it.