I've always called it adhesive ToS. I hate it and I think it should be illegal. You set up an account and all you need is an email address. Then, all of a sudden, they need your phone number "for security." Then your name and DoB "for the security of your account." Soon it'll be a credit card for age verification.

And the whole time you better give them accurate information because if they ever lock your account you'll be expected to send photo ID so they can verify it.

The next step is subscriptions. The entire point of forced logins is because that allows them to build future features as subscription only. Think about how online SaaS works and how everyone eventually switches to a subscription product by keeping, but abandoning the existing service and building all new features on a subscription model. With everyone forced to log in Windows is essentially a SaaS. They're just not charging for it. Yet!

Remember when you could get a free custom domain on Outlook.com or GMail? Anyone on those services was allowed to keep their stuff, but huge effort has been made to devalue and de-market those historical accounts. Microsoft shut down the entire admin side of things and Google excludes them from most new features.

Get out your wallet. Prices are going up.