Just gotta apply like crazy, leverage applications against each other. Tell one you got a better offer from another, tell your company you got a better offer from someone else, etc.

This is basically what marketized labor is and it's bullshit. You are a commodity that needs to be sold. Generating demand for yourself can actually help you get better wages, but only to a limit. Anything drastically good is going to require collective action because the difference between laborers is only small and a group of workers withholding labor can drive up the price of their labor in a market context.