Oftentimes, nothing.
See, when details like this are leaked, the data that’s lost is almost always encrypted: which means that hackers have to un-encrypt the data in order for it to be useful. This is why it’s often faster and more profitable to simply sell the encrypted data for a quick paycheck, rather than steal anything themselves. Even if they do decide to decrypt the data, any strong passwords could take years — or even decades — to be decrypted. So if you’ve got a strong password, you could actually get “hacked” and be fine for a long time.
That said: if you have a weak password, things get bad. A simple password — or worse, a common password like “123456”, can be decrypted in seconds. With this and your email, they can access any account that uses that email/password combination, pilfering your data, stealing your identity, and ransacking your digital life. Just another reason to make sure every account has a unique password.