The side effect could be that they lose a LOT Of money, however the other effect of that would be that the reesulting empowerment of users to just leave could easily send a message to Meta and others to get their act together on a variety of issues, including online safety. Various recent reports say there is still self harm in Instagram for example.
Big tech don't care, they care for profit.
As for the job of their moderators, lets NOT blame them, as with mods here on Fedi they do a great job, under trying circimstances, if I understand this, in some cases they are employed on poor wages and conditions (ref recent lawsuits on the trauma caused). Aim the full blame at the top and the shareholders of course.