Applying a vastly simplified model, every job has a salary range possible:
From the company's side: At most the amount of money you make the company, and at most the cost of hiring a replacement who could do the same job equally well.
From your side: At least the second-best job offer you've received.
Raising productivity is often a prerequisite for raising salaries - but you also need a tough hiring market, if you want the business to give the money to the workers instead of the bosses, investors or customers.
From the company's side: At most the amount of money you make the company, and at most the cost of hiring a replacement who could do the same job equally well.
From your side: At least the second-best job offer you've received.
Raising productivity is often a prerequisite for raising salaries - but you also need a tough hiring market, if you want the business to give the money to the workers instead of the bosses, investors or customers.