I don't think that solves things because I can just come up with a scenario where all these issues don't exist, it's clear what's actually missing is rules like consent.

So, an example without these issues: someone is kidnapped (drugged, it was painless) and a surgeon without consent removes their kidney, to be used to help a dirt-poor dying child. No threat of infection, no hypothetical of it being sold to an exploitative rich person, etc. but we still have the problem the meme points.

Bathtub half full?

I prefer rules-based utilitarianism, which is the idea that we should create a system of rules that achieves the most good when followed. If we created a system whereby we rounded up healthy people and forcibly harvested their organs "for the greater good", well, society would collapse as everyone flees to the woods to preserve their own life and organs. No farmers, no scientists, no doctors, no infrastructure maintenance, just global famine. And that would be a far worse net outcome than the current system that lets some people die prematurely due to lack of available organs.

I thought utilitarianism was "someone got their kidney stolen recently, but I'm more happy to get it than they are sad to lose it". But maybe that's overly cynical.

No shock value :(