[vy8vWJlco]

One could use something like a copy-and-pastable session/state string/encoding (that a user should keep secret, if secrecy is important to them) at the bottom of every important page that a person might want to return to (rather than in the URL or the invisible, and therefore unmanageable, cookie). If they care enough to save it, they have an account (ex, they don't have to fill in their shipping info for the 9th time...). If they don't care enough to save it, it can be automatically deleted after a period of inactivity. (This was a common solution to "saving state" in older video games without persistent memory. It wasn't "too complicated" either. People used it, if they wanted to get back to that difficult boss level.)

A login is a continuation, or a state/session key. So is a link/URI. There's no need for a mandatory "account" just to be able to pick up where you left off, even if it's to continue checking your email. (Though one could opt-in to further "protect" pages with passwords, biometrics, non-invasive mucus swab samples, and so on...)