Whenever you see the in page popup “Login to Some Website with Google” that is an iframe back to Google servers. The less Google knows about me, the happier I am.
Is there a reliable mechanism similar to UBlock where I can just block them?
Web search’s have led to “guides” by Google on how to request they stop making it obvious they are tracking you.
There is a custom filter you can copy and paste into uBlock. I searched uBlock stop Google login on DDG a few years ago and found it, and it worked.