(Even worse are products and services where you need a separate password for different features.)
The better way to solve this is to push for better account portability. We already (kind-of) have this with websites that let you sign in with your Google or Facebook ID. (Unfortunately, these systems still have privacy problems because they share your email, or the web site fails if you don't want to share your email.)
Therefore I'd prefer to have an alternative to oauth with old school account creation on each and every website with separate login/password pair.
Of course that would mean you carrying around a physical token that needed to talk to your browser(s), phone(s) etc.
Passwords should GTFO tbh.
Though I think he will need a more convincing marketing site if he intends for people to try it out.
Every single site needing its own password is a feature, not a bug. Educate people about password managers instead.