Been using fastmail since 2013 and before that hosting my own for about 15 years. I feel fastmail does a lot of things right, for example one near and dear to my heart is proper alias handling in the webmail interface. I think my only complaint is that they rolled out IMAP compatible 'notes/memo' for emails, but you can't use it unless you use the grouped conversation thingy which I don't like.

Also I get the vibe that the company treats their employees properly and not like disposable trash.

Though I'd be curious how they're using AI.

Fastmail is great, my one downside being that it charges per-account (to be clear, you can have unlimited aliases on that account), so if you want multiple accounts, e.x. for homelab stuff, your paying full price for each.

I also use purelymail for the above reason, and while it's barebones I've been quite happy with it.

I switched years back and have only wondered why I didn’t do it sooner.

Tuta is the obvious choice if you don’t mind using their client.