If you’re doing things properly, you’ll know your Microsoft account password or have it in a password manager (and maybe have other account recovery options available like getting a password reset email etc.), and have a separate password for the PC you’re locked out of, which would be the thing you’d forgotten. If someone isn’t computer-literate, it’s totally plausible that they’d forget both passwords, have no password manager, and not have set up a recovery email address, and they’d lose all their data if they couldn’t get into their machine.
Even if you have your Microsoft account password, it doesn’t help when you can’t even boot into Windows.
Most people have smartphones these days where they would be able to log into their account and grab the recovery key if it’s backed up. If they don’t have a phone, they will know someone that does, or a library with a computer.
Bear in mind that non-techy users don’t get the option to opt out of a Microsoft account in the OOBE now, so most should have their key backed up without thinking about it
