Likewise. I ran my own MTAs for 17 years and there's nothing I want that Fastmail doesn't do - and a good bit I do that would've been (was!) at best time prohibitive to set up and run for myself.
I used Google Music heavily -- so much that my local music collection fell into disrepair. When they killed it, I downloaded everything using Takeout. Years later, I'm still dealing with the mess of metadata and (lack of) folder hierarchy that my collection used to have.
My de-Googleification of my life is nearly complete. I just wish I had done it earlier.
I've been using Hey since it was released. It's fine, but if I was going to make the switch today instead, I'd choose Fastmail or Proton instead. I use Fastmail for my business and it's been quite good. Proton conceptually feels like a better choice, but users with Proton-domain emails cause a ton of headaches (fraud, etc.) at work, so I'd probably give them a pass unless you use a custom domain.