your typing about YouTube sparked a bit of a tangential brainstorm in my brain, if that's ok. (related to google's single sign on [SSO] login system)
while its "nice" that we can login once and then be automatically signed in to all the other Google services on iPhone/android/chromeos etc, I also strongly believe that there should most definitely be the *option* for it to *not* behave this way. basically, I believe that users should have the choice.
I think that it would be nice to have the option to login to certain Google properties (Nest, Gemini, Fit, Google chat, etc to name a few) alternative means whether it’s a separate SSO like "login/continue with Microsoft/Apple" or the ability to add an alternative email and password login that triggers a login to *only* the one app, without auto-logging into dozens of other google apps, people should have that choice when using an omnipresent service like google. I do like google services, but we need options for logging into apps in a singular manner instead of always logging us into everything else. In terms of an SSO, Microsoft would be *my* top choice because it seems the most "platform/device agnostic" to me, but others may have their own choices. and then of course, the ability to add an alternative email+password login would negate the issues with Google having to add another SSO.
Another idea i had would be a checkbox *on the login page* - something to the effect “do not login to other google apps (only login to [google service name]).
*yet another* thought related to this is the google apps account switcher security. idea - the account switcher for android / iPhone Google apps works well, but for added privacy/security, maybe there could be an option to require authentication (password, fingerprint etc..) when switching accounts. again, it could just be an *option* for users who want extra security.
anyway, sorry for the tangent, but I kinda like to discuss these topics if that's ok, and you bringing up divesting YouTube kind of made me think of it, if that's ok.