In general, you shouldn't ever reuse a password for multiple things, no matter how complex the password is (see https://xkcd.com/792/ https://xkcd.com/792/). If

In general, you shouldn't ever reuse a password for multiple things, no matter how complex the password is (see https://xkcd.com/792/ https://xkcd.com/792/). If your password is leaked (which might not even be your fault), you don't want the attackers getting access to everything. A large website is made up of many different complex, interconnected components, and it would be quite possible for an attacker to compromise a public account without gaining full control of the backend infrastructure is unaffected.