I just sold a domain I had for 25 years and used for everything including API endpoints, email, authentication, etc. It took a couple weeks to transition myself and my family/friends.

Pretty sure just moving emails would have take a lot less effort. I had the advantage of keeping the domain until I was ready to move, now imagine Google just turned it off one day and what your workload would be. I shudder to think about having to deal with that.