'"From" says nothing accurate about where is came from, it can be anything the spoof sender wants to put.'

Good point that has been missed in the rest of the thread and the linked article. Spammers insert random harvested email addresses in the "From:" field, and that means sometimes YOUR email address is inserted there. When that happens your account hasn't been hacked, and you can't do anything about it.

I'm not saying email accounts don't get hacked, but that's not the only way that a spam message can appear to have come from your email address.

When you do get hacked, often the hackers don't change your password, so you carry on using the account without knowing anything has gone wrong. When you do find out there's a problem and change your password, the hacker has to start from scratch to discover it again.