Clearly I don’t know what your application is, but many heavyweight “web apps” don’t cope with a simple refresh, kicking back to a default screen or even login screen in some cases.

Also some apps ignore simple refresh and only react to hard refresh (ctrl-f5 and alikes). Refresh is as unreliable as other methods from user pov.

Sometimes this is to scope logins to single tabs for security reasons (I think that's why Userify does it that way). It's annoying but for infrequently used apps, no worse than getting logged out every three minutes.

client side state that isn't in the URL or local storage