With two changes the ACA would be the best reform for healthcare insurance I could imagine. First, replace the now eliminated individual mandate with a hefty monthly penalty to add insurance later - something like 150% or double premium for two years. Make it really hurt to add coverage once you get sick to help remove the incentive to insure only when you need it. Something like that was in the attempted 2017 reform. Second, increase the cap for subsidies to keep premiums at a certain amount of income to something much higher even as the fraction of income taken up with healthcare costs rises with increased ability to pay. Current it caps at 4x the poverty level and 10% of income applied actuarial to health care costs (premium, deductibles, and copays). Make it more like 12x or 16x poverty and caps at 25% or so of income at the top of the subsidies. People are still responsible for their costs, but only to a certain point.
After that, then we need to actually fix healthcare which is an entirely different matter no one has really taken on yet.
