This is a standard story in the crypto recovery business. We have dozens of clients who come to recover their wallets, and they are sure they don’t have the necessary recovery information, but after a good search they find the right clues.
Your story is quite unbelievable because a more popular story I knew is people did not make back up and they forgot wallet passwords, forgot any clue, did not have wallet mnenonic seed backup, did not have private key backup.
Usually by lack of careful and proper backups, later they had nothing left for recovery and lost their wallets and bitcoins. It's very common story with non custodial wallet users.
They can recover their accounts on centralized exchanges without backups but it takes time and centralized platforms with custodial wallets are not good to store their bitcoin.
Reminder: do not keep your money in online accounts