Most people aren't actively violating a contract in meat space. This isn't about people doing 2 real jobs. This is about people doing 0.25x at 2+ jobs. They are lying and screwing over team members who have to pick up the slack and deal with their BS.

They're not fighting the man, they're the person who shows up on the last day of class and slaps their name on the group project. These aren't a new class of individual arising from the pandemic or remote work, it's a situation which is emboldening pre-existing bad behavior.

Firing is a pain in most orgs. Telling other employers that this employee behaved like this is illegal, so they keep doing this in more places. It's plain old theft and disrespect for team members.