https://en.wikipedia.org/wiki/Impact_factor
Therefore is a captive customer case. And captive here has the same meaning as slave. If you don't work for free for some journals, basically you can't have a scientist career. In higher levels articles are not enough and you need to consider seriously to write a book for Elsevier or somebody else.
And this cut both ways. Acta Vertebrata, the journal of the Doñana's Biological Station since 1974, have to be closed in 1997 after decades trying unsuccessfully to achieve a higher impact index as journal. Low impact index means that you obtain less and less of the researchers effort and that interesting articles fly away your radar. Researchers deciding to publish in Acta Vertebrata had a competitive disadvantage. It was a terrific journal, the problem is that they did science in the latinosphere, period. Nowadays science means do politics or go home