I have a free Google Gmail account and can use all those free features. I never signed up for G Suite or Workspace. I think the problem is when a personal domain name is used.

I'm glad I moved from Gmail to Fastmail a month ago. After they screwed me over with Google Sites V2, I just don't trust them with my email address. It's tied to too many things, and if something ever went wrong, I'd be completely screwed and could not get any help from Google. I clicked their "Report a problem" button when trying to migrate to Sites V2, to report several big issues. I'll let you guess how many responses I got.