A long time ago (2008), quite literally in a land far, far away, I gave a short talk on how I'd started using Google Apps For Your Domain. Prior to that, whilst studying for my MCSE, I'd set up an Exchange server environment on old desktops at home, and run my email &c off that. Moving to GAFYD saved a lot on the electricity bill, and my time on admin overhead.
13 years and two product names later, I was in the same position with Google Workspace as I had been with Exchange. It was costing more than I wanted to spend, and the complications of using it as an every-day Google account were getting tedious, and I no longer needed push email notifications (my personal email is mostly a receipt repository): I'd already done enough migrations between Google and O365 to have reminded myself what I think of Outlook, and felt the particular lemon of corporate Google was fully squeezed. I wanted to keep using my domain for email, but without the overhead and snags of the corporate product.
Deciding to leave Google Workspace is one thing, executing it another: I have a lot of photos in Google Photos, and a lot of data in Drive. I'm not trying to leave Google completely - I just don't think there's a realistic replacement for their browser-based office suite and spam filtering - just save a few currency units and simplify.
After some research, I found someone else's work to copy: https://www.39digits.com/migrate-g-suite-account-to-a-personal-google-account
Chris seems like a sensible person: doesn't like Brexit, is embarrassed by the UK's COVID response, rejects Facebook. His documentation is good, too, with plenty of detail. I've made a shorter version - just a checklist - that you might find helpful:
- Spam: when importing mail, I noticed Gmail was marking a lot of email as spam that wasn't, so it's worth checking the spam filter.
- Photos: Google Photos didn't recognise any faces in the photos until the old GAFYD account was deleted: once I'd deleted the account, it recognised faces again, although had to be re-trained.
- When setting up Gmail on my iPhone, I need to set the address to my domain's address, and not the gmail account address, as otherwise the iPhone would try and reply from the incorrect one.