We could spend less money.
In Education we spend far more than the 80's and have less to show for it.
In healthcare we have astronomical costs that have not bought us more vitality, but an extended morbidity. Gone are the days of grandmothers with sinewy arms maintaining huge gardens. Obesity in the early 2000's was at "crisis" levels and it's gotten so much worse that we just stopped talking about it. But we can keep the numbers up a bit here and there.
In infrastructure we let car-first build-out destroy everything Jane Jacobs said we were going to lose. Valuable things that cost no money at all, but are too intangible for top-down planning to notice.
The failure of imagination isn't finding new people to juice. It's finding ways to be effective. I agree they are very bad at their jobs, but I don't think finding a new way to tax the rich is any more creative or sustainable. I think it's the same failure of imagination that you fear.
We could spend less money on healthcare by adopting Medicare4All or similar.
We could cut the military budget _dramatically_ without impacting our national security.
And yet both parties have done little but increase the extent to which our countries is beholden to banks.
If you think you can replicate the healthcare success of [pick your model country] without also replicating their obesity rates, doctors salaries, amount of testing and prescriptions, etc, you will find that who pays for it all is the least of your concerns. As Americans consider it, we probably have too much "healthcare", not too little.
Others have spent far more time than me on this if you're interested: https://randomcriticalanalysis.com/2020/01/31/i-created-a-pr...
The stuff about pharmacy benefits and doctor salaries are artifacts of our weird way of paying for things. I'm not sure why you're portraying them as separate, isolated issues.
We just need to fix billing, end price fixing, and massively deregulate - certificates of need, bans on telemedicine, pay for procedure etc. This will actually fix it. Medicare and Medicaid are incredibly expensive and inefficient.
This appears to be, at the very least, debatable:
Even funnier is we can blame our covid 19 failures on being unhealthy: https://www.cnn.com/2020/05/17/politics/us-health-conditions...
Obviously this a bit of shift the blame (played by both parties), but we can see that reaching for this argument means we really have failed on the healthcare and preventative medicine side - covid19 just calls this out.