I'm sorry you have to deal with that, what an awful situation, and how lucky your family member to have you around to advocate for them. I don't have much to add as I won't pretend to know the actual delivery of healthcare better than you.
But I agree that our system is basically broken so badly that I don't know how to reasonably fix it. Like, sure we could do things. Single payer. Eliminate for-profit healthcare (somehow define that properly, whatever "properly" even means). Align processes nationally so your situation doesn't just get dropped.
Canada, Asia and Europe all have issues with their healthcare systems, but they're still orders of magnitude better than what we have here. We go on and on and on about how we're the best country in the world but... my god are we behind.