No it's not the mismanagement, apparently everyone loves their "government managed" medicare. They just need to give it to everyone. The reason why they don't is because of the corruption which makes politicians pledge allegiance to rich, corporations and special interests and do their bidding to the detriment of the general public.
There is always endless money to pay for yet another war, tax cuts for the rich and corporations as well subsiding farmers, oil companies and multi-billionaires like Musk and Bezos so they can continue their galactic d!ck measuring contests but never enough to pay for education, healthcare and infrastructure.