People not doing this is why it stays as it is.
If you don't like your broadband provider; you change it. If you don't like a car brand; you don't buy it. You don't buy them and claim their deficiencies are unfair.
Demanding change can also work, and regardless of whether better alternatives exist.
"Just move to a country where women can vote" was not an effective strategy, demanding the vote worked for a huge number of women without them even moving to the next town.
You thought A is great but you think you can find better so you go to B. They turned out worse, you then tried C and those weren't great either. But now A won't hire you back because they already filled the position, and there are no other available companies doing the thing you want to do. Now you're stuck with inferior employment options compared to the choice of not changing jobs in the first place, unless you're willing to do something else entirely or start your own business.
Depends on the field obviously, but there are reasons why people might want to stick with a not-so-bad job instead of looking for a perfect one.