Yes, it does; but it's not how much value you, as an individual, add, but how hard it would be to find someone else who could add the same value but would work for less money.

> If companies can pay less and get the same value, they totally will.

Yes, which means companies are aware of how much value an employee adds; they are just also aware of what the current market price is for that amount of value. Whereas, many employees are not aware of that.

In any case, the primary benefit of the observation that the more value you add, the more you get paid is long term, not short term: it tells you that, if you want to increase your total lifetime compensation, you need to become harder to replace. In other words, you need to add, not just value, but some particular kind of value that fewer other people could add if they were hired in your place. The scarcer the kind of value you add is, the higher the price you can get for it.