Eli5 Why is it necessary to change email passwords if that email was breached from a completely different website?

Question

I never understood this. If my email (gmail as an example) got leaked among other thousands or millions of emails from a data breach from a website that I’ve signed up in, why then would I need to go to Google website and change my password if I would be using different passwords for these separate websites?

Or perhaps I answered my own question? Is it on the off chance that I or someone else *would* be using the same password across multiple websites? Should any actions then be brushed off if I *do* use different passwords?

In: 11

Answer 1

You are exactly right. Many people use the same, or similar passwords across every account. So you are told to change them all, aswell having unique passwords for each account