Nope, no hard border. Just progressively more difficult (and not linearly). My assumption is that, because any such large-scale human endeavor is a network, the complexity increases by some superlinear rate with size unless a almost superhuman effort is effected to counteract that.
Even in the 50-90M range, healthcare systems start to show serious orchestration/efficiency/coordination issues. Healthcare is just the final boss of this type of thing, because everybody needs it and there actually isn't enough to go around.
Regardless yes, I think the US should definitely have states try to figure this out at a smaller scale before even thinking about trying to achieve it at a national level for 300+ million people. Added benefit that some friendly competition amongst states might actually help move things along.
I would actually say it can only scale linearly or slower than that. Either you gain efficiency due to economies of scale, or worst case, you make 10 smaller systems.
But I still don’t see how the scaling would be worse than linear.
How is managing 300 million people more than 3 times harder than 100 million people? The effort per person shouldn’t increase, and everything common scale lower than linear.
10 smaller systems then require a layer on top to manage those 10 systems. Now you have 11 systems. And there definitely won't be only 2 layers in your public healthcare system for 300M people across 50 different states.
Have you never worked in a large corporation before and seen all the intermediary layers of beauracy? If you have, imagine the largest company you've ever worked for, multiply it by 1000x, and then imagine but there is no profit motive driving efficiency (or competition) and your customers all demand access to a resource that is finite. Except they're not really "customers", so you can't say "sorry no more product left, better luck next time".
That is publicly funded healthcare at scale.
What "economies of scale" do you imagine centralized publicly-funded healthcare has?
Even in the 50-90M range, healthcare systems start to show serious orchestration/efficiency/coordination issues. Healthcare is just the final boss of this type of thing, because everybody needs it and there actually isn't enough to go around.
Regardless yes, I think the US should definitely have states try to figure this out at a smaller scale before even thinking about trying to achieve it at a national level for 300+ million people. Added benefit that some friendly competition amongst states might actually help move things along.