True you possibly couldn’t get that y on your own. But someone got it, and it wasn’t you.
If my neighbor wants a new fence (the Y), offers me $50 to dig a hole (the X-Y) to put a fence pole in.
I dig a hole, i get $50. He gets closer to a fence. we have both profited, who is exploited?
Or if you want to go even more basic:
he wants a fence, he pays me $500 to build a fence, i build the fence and get $500. who is exploited?
Note these are real examples from real life that i deal with.
The value of the fence is X and you got X.
For me it's $500, for my neighbour it's $5000 - because it stops rabbits from eating his garden and stray dogs or whatever.
If it's $5000 value to my neighbour, should I have charged more even though I would've accepted $500? Who would have been exploiting who then?
This is directly analogous to my employer as well, except replace "neighbour" with boss, and "fence" with code. It's still a voluntary trade.
So yes, if it’s worth more and someone pays more then you get more. That’s not at all the point.
But if you are paid per hour and you produce many more fences than is required to pay your wage, you are being exploited.
If my neighbor wants a new fence (the Y), offers me $50 to dig a hole (the X-Y) to put a fence pole in.
I dig a hole, i get $50. He gets closer to a fence. we have both profited, who is exploited?
Or if you want to go even more basic:
he wants a fence, he pays me $500 to build a fence, i build the fence and get $500. who is exploited?
Note these are real examples from real life that i deal with.