How about not needing an account for things that don't need accounts?

I've just bought a Lego set for my nephew's Christmas present and I couldn't just check out with my credit card. No. I had to create a Lego account and join some sort of community thing with nickname, personal page and reward points systems and constant email spam. And of course two days after that I get informed that they were hacked. I can't wait for the damn set to be delivered already so I can delete that account.

Your forgetting in between each step where it asks you which 4 of your orgs SSO accounts you want to use.

Daily.driver@yourcompany.com
Elevated.account@yourcompany.com
ThatOneWeirdAccount@yourcompany.onmicrosft.com
TheOtherAccoutYouForgotWhatItWasFor@yourcompanysolddomain.com

Shouldn't we reboot the internet and do it right from scratch, without compatibility to some 1980's limitations and without executing foreign turing-complete code?

Passkeys aren't actually bad, they just make the "remember my password" flow slightly easier and more secure.