I don’t know who needs to hear this, but there is only one reason to give two weeks notice (setting aside contractual outliers).

That reason is to receive a good reference. If you know you won't get one, you have no reason to give two weeks notice. You might imagine you do, but you've been brainwashed and intimidated into believing that is a legitimate reason. There is not a thing an employer can do to you that would not substantially fuck them over ten-fold.