I host my own email and most of the time I don't encounter any technical problems: I got rejected once (last week) since I started last year. Most of my problems have been trying to tell/have people read my non "@gmail/outlook/yahoo" domain! Probably depends on how you use your email, but it's been smooth pretty smooth sailing personally.

IIRC, you avoid most of the problems if you set up your DNS accordingly (DMARC, SPF, etc). But for a mailing list AWS SES is probably the way to go to avoid all the trouble.

Probably yes. But my best guess is most of them use AWS SES or a similar provider for the actual outgoing emails to avoid exactly this problem.

Control, hygiene, the fun of bayes filter magic, strange prtocols like imap, your own gpg mailing lists. Internet 101.

Then is there much of a cost-advantage to self-hosting or is it more about control?

Comparing with MailChimp and co, I’d say it’s definitely cheaper (going with SES for sending mails at least).

I like it because I own the data of my email lists and in this sense, the control is also a big plus point! Plus it’s open source, probably easier to get something custom working than with any big provider out there.

Exactl DANE. Cherry on too, DNSSEC. Running DNS, powerDDS, for instance is also fun.