Aside from the fact that I can't keep the way the auth flow works in my head for longer than 2 days before my understanding of it becomes fuzzy again, a layman is not supposed to understand what's going on at all. Because if they were, they would ask "does this service get my XY password if I enter it here?" and unfortunately, trying to get this answer will lead them down a rabbit hole of auth flows, OAuth2 vs. OpenIDConnect and whatnot, because it's only ever documented for implementers.
The normal user is to just believe in its trustworthiness, which may on a technical level be warranted or not, that's not the point. If you keep logging in with XY to different services, you become conditioned to not question anymore whether it's correct to enter your password right now, and where the login form, which always looks the same across different services, comes from.
But oh well, I don't know what the solution should be here, maybe mandatory 2FA yet again, or passkeys. The market will decide.