i am trying to get active again in some old social media accounts that i still have valid passwords for.

many web sites have a way to reset a password if you know the email. the other way around does not work since it is not possible (yet) to send a message to a password (to maybe reset an email address). and they probably don't keep passwords for security reasons, hashing them instead.

email addresses are volatile. many companies that offered email services have gone out of business. many people had many email accounts expire. email address info was not typically required to login so people would typically save only passwords. many password saver applications lacked a place to save an email address.

two major social media sites (names not divulged here) just don't comprehend the concept that people just don't have access to old email or even know what those addresses are. their support help to regain access covers cases where people do not have the old password but do not cover cases where people do not have the old email address. in my case, many email addresses were lost due to companies going out of business, and a great many (billions and billions of possible user names) were lost due to domain names that expired. does anyone here have a clue why the people that run these sites have such limited understanding of email addresses?