Peter Norvig at Google gave me an invite a few years before it was released to the public. For over 20 years it has been useful for me and my family, but now I just use that very old email account as a reliable backup email. Off topic, but ProtonMail has I improved so much over the years that it is now my go-to email provider.

I have twice paid for and used Google Workspace for my personal use (I like CloudSearch) but it was a nuisance having all the stuff I buy from Google (books, movies, music+, YouTube with no ads, GCP cloud services) attached to my free Google account vs. heavy heavy use of Google Workspace. It would be great if Google solved that problem.