Out of curiosity, I went and checked my legacy AOL email address to see if it's been compromised due to known data breaches on
HaveIBeenPwned.com. A service which was started by a Microsoft Regional Director.
It indicates that my AOL address has been previously exposed on five data breaches in the past. Including various info attached from compromised websites though no passwords. I've changed my account password a couple of times since the last breach. Not really surprising as the same AOL account has been used on multiple sites, which increases the likelihood of being exposed to various data breaches over time.
These compiled lists of compromised email accounts often end up on the dark web available for sale fairly inexpensively, and can contain billion of compromised accounts.
My moderator @gmail.com account which is used only for RV.Net indicates no previous breaches. Likely because it's exclusive for this site.