Parent: "Can you give me the details for the social media account you set up for my business?" "Sure, just log into facebook...", "I don't know my password", "OK... lets log you into Lastpass", "I forgot the password to it", "Right... lets do Screen Share", "I can't log into my computer", "...<silent facepalm>... OK lets reset your password with your iCloud account","I can't log into that either"
The story ends with a fresh new installation of macOS, a Backblaze subscription, two user accounts ("no, look, I know you're married but you're not 'one person' - do you share an email address? phone number? passport? driving license?"), LastPass for both users with browser extension, and their master passwords written down somewhere safe.
Turns out, before this happened, they were logging in using the Guest account to log in on a daily basis (for some reason). Which meant as soon as they logged off, macOS dutifully deleted all of their files from the Mac. Like their weekly take spreadsheet. Which weren't backed up anywhere.