The evidence from health care systems in other countries suggests that this type of excessive rent seeking does not exist in regulated markets. It’s the lack of regulation in the US that is the problem, not the other way around.
A less nuanced explanation is to agree that in an unregulated market, this type of excessive rent seeking would not exist. The old and sick would simply die in the streets. (Actually that's not quite fair since in an unregulated market we wouldn't have streets.)
Obamacare alone added 20,000 pages of regulations.