> I’m interested in what other people in a similar position have done.

I have left Gmail (everything Google, really, that was the last one) years ago when they went back on their word of grandfathered lifetime access to a free email inbox with a custom domain. They did go back on that going back near the end of the deadline, but by then I had already deleted my account.

I switched to iCloud+, because it was the cheapest option I found (0.99€/month) and it includes other niceties such as 50GB iCloud Drive storage, iCloud Private Relay, and Hide My Email. So far, no regrets. It may not have all the features of other email hosts, but it’s enough for my needs and the price with the extras make up for it.