There is no benefit. The benefit is for the legislatures who passed the law. There was no way that we'd get single payer here in the US because our Congress is very much in the pocket of the health care industry. As such, the markets were a compromise measure enacted by congress to make it easier for people to choose health care. Before Obamacare, it was sort of a black box where only HR people could figure out pricing structures and health care providers didn't really compete in any way with each other.

Obamacare did do some good things that needed to be done, but essentially, everything about it was a bandaid intended to kick this shitty system down the road to the next person who had to deal with it. But hey, at least health care companies can't just turn you down because you have Diabetes or are too fat anymore.