Google is almost certainly doing this because the iOS was not found to be a monopoly, while Andorid was. It came up in Google's appeal of the Epic case verdict, where they directly asked the judge about it. Turns out you can't be anti-competitive if you don't have [allow] any competitors.
Wait until age verification is mandatory everywhere. :)
I can already see that happening, e. g. to access financial transactions or government apps, one needs to verify the id, and that will not work without age verification that can not be tampered with. So Linux will either submit to the same or be excluded.
(That free developers will be able to run Linux fine for much longer will also be true, but I guess they only care about catching the 95%, not the 5% linux users ... and 5% is a high guesstimate).
Edit: To clarify the above, one already had to provide personal data for financial transactions, of course, so a bank knows who is who, but the recent age verification go hand in hand with the attempt to get rid of vpn, and applications now make it a new standard to query the age of users, with the claim to "help protect kids". And some people buy into that rationale too. I don't, but I have seen many non-tech savvy people submit to that justification.