Because half the states in the country don’t have the money, while the other half have plenty. GDP is largely centered around large, metropolitan areas with high production and consumption.
It’s not too large and unwieldy to do it federally – actually, it would make everything easier. Ever worked in the medical field, particularly in things like record keeping and billing? There’s a shitload of different standards across the country because it’s all privatized and everyone wants everyone else to adopt their standard so they can rake in a shitload of money for merely creating a standard. It causes a ridiculous amount of issues when hospitals have to transfer mass amounts of data. Not only that, but under the current system, the government has no leverage at all. Why would hospitals accept government healthcare when if they partner with private insurance, they can gouge the shit out of people?
If it was all regulated and controlled by a centralized body, transferring data between hospitals would be as simple as just sending it. No need to do a ton of reformatting and processing if it’s all in the same format across the country. Hell, it could become a mesh network of sorts so with just the push of a button and consent by the patient, their medical records could instantly be available in Hawaii, NY, or Texas. Plus, standardizing it allows the government to say “yeah, no more price gouging and unfair pricing.”
I’m all for capitalism for things that aren’t essential for human survival. But things like Food, Water, Electricity, Education, Medical care, Shelter, and even increasingly the internet as everything in society revolves around it now – all of these things should be tightly regulated. A system built around exploiting people’s literal needs for a profit will never end in a system that actually helps people by and large.
I’m not saying every one of those things should be free, some should and others not. But, it should be very tightly regulated, to make sure the needs of every single person are met (or at least an honest, sincere effort is made).