Nobody under like 40 uses email for personal communication.
Yeah it's a legacy medium for stuff like your bank, maybe it's the least terrible option for B2B communication, but email has largely been replaced already.
It's the default: you need an email to make all those other accounts. Everyone has an email (assuming they have internet at all). Not everyone has a goofacetwat account, or whatever the newest thing is.
...and if you treat it that way, then it's not a "horrible medium" (for "publicly", I would prefer to substitute "on the record").
If you don't like email, that's cool; there are plenty of other messaging services you can use instead. But:
- Your bank doesn't use them
- Your friends don't use them
- They are usually proprietary and opaque
- You might lose your account, with no recourse
Email is the universal baseline, the single communications channel that nearly everyone has access to.