At the very top, yes and unfortunately many workers on both sides of the fence run interference/collaborate for those at the top it’s one of reasons the Molly Maguire‘s never win or rarely win for too long.
Left/Right alignment is relative, and the American political center is...where it is, and has been drifting rightward since Bill Clinton's "Third Way".
I think you mean who will protect the interests of the consumer? That's ultimately who loses to unions. There's no direct ethical value in protecting businesses or their owners but workers and consumers include pretty much all humans and their interests are in tension with each other.
Not generally, no. Workers usually do have choice - they can work in a less desirable job, just as consumers can buy a less desirable product. At the extremes, both are serious - workers without income can starve and consumers for whom food is too expensive can starve.