Or maybe intentionally screwing people (coworkers, your employer) over is an unethical thing to do even if we lean into the extreme credulity you profess here and say, "hey, we don't know if this poster signed one of those special 'FYI I will be screwing you over' contracts, it is not for us to make assumptions, we haven't reviewed the contract."
Nobody owes their employer any more than the minimum that is guaranteed by the employment contract. Sucks, but that's life.
If you feel like the quality of your coworkers that give minimum effort is screwing you over, talk to your employer.
If an employer can be picky enough that they require you to only have them as your only employer, they would need to specify that in an employment contract (it's not enforceable, you have a right to privacy from your employer).
If you want to be "ethical" (ie, servile to your employer) to the detriment of your economic survival, that's fine. That's your choice. Everyone else is going to play the game to the rules.
