I used to pay for Gmail, then I used Proton Mail about a year, and I’ve been using Fastmail for the last couple of years, which I recommend. I don’t know of anything that’s as feature-rich and easy to use as Fastmail. You may not be interested in all those fancy features, though.
I use MacOS/iOS Mail clients, but also Thunderbird as I’m trying to wean myself off of Apple’s ecosystem and onto Linux/FOSS.