My point is very simple and we do not have to discuss all the edge cases. Working x hours and consuming stuff that took y hours to produce where y is much larger than x is unjust. All the rest are details.
I make widgets. I work 8 hours and make 8 widgets. In my spare time I make a machine to make widgets for me.
I've finished my machine, and it can make 16 widgets in 8 hours as long as I turn the crank. So I sit and turn the crank for 8 hours a day and make 16 widgets. Am I immoral yet? I just doubled my productivity for the same amount of work.
Now I pay someone to turn the crank for me. They work 8 hours and I give them 8 widgets, and I keep the other 8. They are doing the same 8 hours of work that I was doing, and I do nothing but make sure they keep turning the crank.
Am I immoral now? Why? I built the machine and I get 8 widgets a day out of it, the same amount I got when I was building them by hand. The crank turner also gets 8 widgets in 8 hours, the same amount I was producing by hand.
So the crank turner does less work for the same output, I do no work for the same output. But both of us have the same resources as my competitor who makes 8 widgets by hand.
Is it moral for the crank turner to exchange their 8 widgets for his? What about me?
How am I controlling others? They are willingly turning the crank. They still get 8 widgets and they do less work than if they built the widgets themselves.
Everyone is doing better in this scenario than when I was building the widgets alone.
Sure, everyone [1] is better off, but that just sets the bar too low. You and the other guy each turn the crank for four hours, that is the fair outcome. If you insist, you get a couple of extra widgets for inventing and building the machine.
You spend a week building the machine, time worth 40 widgets, but you want - ignoring your finite lifetime - infinite compensation for that, free widgets forever for a 40 widget investment.
[1] A bit nitpicking, in the exact case you presented, the other guy might not actually be notably better off. Instead of manually making eight widgets for himself - assuming he is as skilled as you - per day, he now spends four hours making his widgets and then four more hours making your widgets. This can of course easily be tuned to actually make him better of or that might already be the case if turning the crank also improves the working conditions over the manual process.
What then is a more fair outcome in your original scenario where producing widgets was the only activity?
If you keep working, making other inventions, that is a completely different scenario. That you should do your share of crank turning only applies to the scenario where turning the crank is the only work that needs to be done.
Are your subsequent inventions better than the art they create?
Do we really need double the widgets?
I mean, the top post on this site yesterday was a self-balancing cube someone invented. This is precisely the community that should understand that inventions for inventions’ sake aren’t necessarily improving anything.
I've finished my machine, and it can make 16 widgets in 8 hours as long as I turn the crank. So I sit and turn the crank for 8 hours a day and make 16 widgets. Am I immoral yet? I just doubled my productivity for the same amount of work.
Now I pay someone to turn the crank for me. They work 8 hours and I give them 8 widgets, and I keep the other 8. They are doing the same 8 hours of work that I was doing, and I do nothing but make sure they keep turning the crank.
Am I immoral now? Why? I built the machine and I get 8 widgets a day out of it, the same amount I got when I was building them by hand. The crank turner also gets 8 widgets in 8 hours, the same amount I was producing by hand.
So the crank turner does less work for the same output, I do no work for the same output. But both of us have the same resources as my competitor who makes 8 widgets by hand.
Is it moral for the crank turner to exchange their 8 widgets for his? What about me?