It would be optimal for all researchers to coordinate to move away from Elsevier, but as long as everyone else (or the majority) is publishing in Elsevier the local optimum for each researcher is to continue publishing in Elsevier.

I know a few researchers who have publicly committed to not publish in Elsevier journals, but there's a career cost to doing this, particularly for early career researchers. Outside of a small number of colleagues who will actually read your work, most people (including funding organizations and tenure review boards) will judge your research by how much you publish and where you publish, and Elsevier owns many of the most prestigious journals.

It varies by field, depending on how many journals Elsevier has managed to capture. I consider myself lucky that Elsevier doesn't own any of the major journals in my specialty, so I've so far been able to avoid them without feeling like I was making career sacrifices to do so.