You get paid depending on how hard you are to replace. This kind of labour can be done by basically anybody.
Sure; companies have long gotten away from dumping their externalities out on the societies that host them. Criticism of this sort of thing isn't arguing that it's not legal; the argument is that it's bad.
As Amazon is discovering with delivery drivers, at one point you start running out of "basically anybody"
Yes, so the conclusion is that political agitation is necessary if the goal is to change those working conditions