alt Hacker NewsI think the concept of a user having an existing Gmail account if they aren't in the Google ecosystem is a bit of hubris.
There are many people I run across who bypassed the whole Gmail and Google Workspace ecosystems and have rolled along merrily with me.com and other email providers.
It's not a given that users will have bothered to register for a Google account unless they grew up in the Bay Area after a certain time period.
Wind back the clock to when Google tried to roll out Hangouts and the Gmail penetration rate was even lower among the non-Android users out there.
I'm just thinking of my own friends and family, who are mostly not tech nerds and none of whom live in the Bay area. Gmail launched with so much more storage than any other free email service everyone thought it was an April Fools joke (no doubt in part because it was launched on April 1). Everybody wanted it, and nobody who got an invite code before I did would give me theirs.
This is all anecdotal of course. Maybe it wouldn't have worked, but how quickly they gave up was weird.