Oh boy.
There are two root causes of the unsustainable cost inflation of "healthcare" (regardless of how you play the shell game of premiums vs deductibles vs government slush funds to fill insurance company profit gaps vs etc, etc).
1) Health care is a fee-for-service system. The incentive here is not to provide a quick, effective outcome. Fairly obvious.
2) On top of #1, we employ the completely idiotic, ultra-inefficient THIRD PARTY PAYMENT SYSTEM (...that means YOU..."insurers").
Focusing on #2... Health insurance is a major scam. It may not have started out as the health insurers fault way back when, but what it has evolved into is gross. It's not "insurance" at all; it's a "medical payment" industry where a middle man ("insurers") skims money off of each transaction. Add the zero transparency regarding medical pricing, and you have a system in which no one knows or cares what things cost. This makes it impossible to actually allow the market to work toward supply-demand equilibrium, which ultimately generates true "cost" (see any other industry).
Regardless of premium increase figures (see aforementioned shell game being played on the public), the ACA did NOTHING to address these two root causes. Everything else sits on top of these inefficiencies and truly has minimal long-term impact. All of the major provisions (I can go into more detail if needed) of the ACA increase demand for health care across the board. And what does increasing demand for something do?