I would imagine that the health insurance profit margins are relatively low compared to the rest of the economy. 5.5% is not the holy grail of capitalist profit margins.
I have not really looked at insurance market profits in the last few years, but they were running 80% margins during the last major hurricanes in FLA. I remember the figure because it really baked me that with a margin like that, they weaseled out of payment, asking the gvt to cover them or they would go bankrupt.
Even if I accept a 5.5% margin, surely there is a reason why all the health facilities are owned by insurance companies and pharmaceuticals.