True. But servers have advantages, like being able to get to my email from anywhere. I remember the dark days of POP...

Not really - setting up a mail server is actually pretty easy if you ignore spam detection algorithms.

Email/SMTP is a very fault-tolerant protocol, which means it's very forgiving to a whole number of different errors that you can make while setting it up.

The problem comes when you account for the facts such as (1) some ISPs block ports commonly used for email; (2) some email providers will mark email from self-hosted email servers as spam.

But none of that is about email/SMTP specifically (and could theoretically apply to any P2P solution that catches on).