I was meaning more for individuals, rather than businesses. If your business is in G Suite, it is possible to migrate off as you do have your own domain name,

I was meaning more for individuals, rather than businesses. If your business is in G Suite, it is possible to migrate off as you do have your own domain name, just point your DNS records to your new server, and generate new mail accounts. I was meaning more for personal use. I don't want my personal email address to be at the whim of Google, which it would be if I used an @gmail.com email address. Obviously my email hosting is still at the whim of the host, who, like Google, can just cut my service if they want, but that's always a risk. I could host my email on DigitalOcean, but DO could cut my service. So I could host it on my home computer, but (ignoring spam filtering problems and uptime) my ISP could cut my service.