Can you make an argument as to how this is different from having to have an account with, say, your ISP?
Your ISP is an utility, it doesn't hold your de-facto identity.
Google and Apple increasingly become the entity required to identify yourself, either directly ("login with Google/Apple to participate") or indirectly ("use our App on iOS/Android to confirm your identity and participate")
You have many ISPs to choose from. There are not many "Googles" nor "Apples" to choose from.
If ISPs pose a similar problem, that still doesn't minimize the Apple/Google problem.
This question is a non sequitur.
No one is arguing for using ISP-hosted accounts as an alternative.
The core problem isn't even rooted in identity per se, it's about platform owners actively working to limit access to essential information from platforms they cannot profit from.
Even granting the most cherubic motives, this ongoing behavior is atrocious on it's face and should be prevented by any means, including competition, rule making and legislation.
A few points:
1. It's not necessarily different. Your ISP has monopolistic power over you, and it should be regulated more aggressively.
2. A non-mobile ISP is currently much less important than an Apple/Google account for interacting with modern society, and less important than it was even a decade ago. If all 1.5 of my available home ISPs turned evil I could manage just fine without them.
3. Given the relative public perceptions this feels weird to say, but Comcast and their ilk are much less problematic than the Apple/Google monopolies. You can largely just pay for internet (plus an extra 10-40% from scammy business practices) and do whatever you want to do, with the analytics they're selling about you being less invasive than those which Apple/Google use.