Yeah, fastmail has some issues (see below), but they offer human tech support that ime knew what they were doing, even at the $40/year price point. And they seem to have slightly raised prices while I've been a customer, but automatically grandfathered me into the previous deal. Which is kind of them / a stand up thing to do.
Issues: they've fixed many of them -- in particular, charging for 2fa at $0.1/sms and the settings area in the web client used to feel like a bad programmer's first js project ever -- but mostly it comes down to, across almost all experiences, they're slightly to mildly inferior to gmail. Google's apps are just best of breed. Fastmail is the best non-google I've found, and I looked pretty hard a couple years ago.
Things I miss from gmail are things like: fastmail is a hybrid conversation based email with folders rather than tags. I miss tags; some folder weirdness occasionally peeks through. Fit and finish like after a message is selected, choosing add rule from message doesn't offer to filter other messages in your inbox that match the new rule. Etc.
Paying $40-ish/year to have email that isn't used for ads and that is run by a company with actual support seems like a good deal to me. Particularly if you don't have a friend inside google or the ability to hit the front page of HN to get customer service.
You can see the improvements in fastmail even over the 3 years. So that's really promising.