And at certain curve the amount of money yoh make matters a lot, if you have base expenses. Making 4k vs 2k is technically infinite gains if your expenses are 2k. If you become more efficient, but don't make more money, then you clearly need to work on your ability to sell yourself. And if your expenses also grow equally to what you are making more, that is also on you.

First, it assumes that you will be paid for said productivity. If you are doing piecework or sales or something where your income has direct proportion to your paycheck, this is true. For most people working hourly or salary, this is not true. As you mention, you're paid by how you sell yourself. This is only nominally related to how well you do the job above what is expected.

(If you get a 2% raise for being adequate, 4% for going above and beyond, and 15% for working on your interview skills and jumping ship, your productivity system is not what matters.)

Side note: price-fixing cartels are black letter illegal as fuck in the US, but we don’t seem to enforce the laws against corporate landlords