[arghwhat]

In salaried positions, "overtime" is either rewarded with a raise or promotion.

For the types of job you are thinking of where overtime is entirely uncompensated (such as a lot of developer gigs), you are not really working overtime. You are working exactly what was expected from your employer. Any less, and you'd risk losing your position. Different jobs have different expected baseline work.

However, work above the expectation should still be compensated, and if it isn't, you're also within a group of people that is likely able to quit and find a different position at higher wage, or just a position where hard work will be rewarded. That is definitely the case for the developers here.