I'm not being exploited any more than I'm exploiting my employer, that's a toxic way to look at voluntary interactions of people doing their best to escape suffering and death.
There are many problems with modern capitalism and the political economy of the world. If you have ideas about how we can build a better system, I genuinely wish you luck.
The difference lies in the power dynamic: if you don't like the terms, you can look elsewhere to find a better fit; if the employer doesn't like the terms, you may find yourself out of a job faster than you can replace it. For some people it may not be a big deal, but for many it's a significant factor in how hard they push for what they feel would be fair compensation.
No it's not necessarily, because employment is a repeated game with public information.
(Other people can see how much you're paying people by checking levels.fyi/blind/etc.)
There's better ways to motivate people anyway - thus tech companies pay with stock grants and performance bonuses.
It's mutually beneficial (otherwise one party or the other would terminate the contract), but that a wide window for the balance of benefits to shift.
"Voluntary" is not a word I would use to describe any agreement where one side is choosing between the deal and physical danger or potential death.