The paper considers that hypothesis and rejects it, honing in on prices not utilization as the problem. Indeed its title is "It’s Still The Prices, Stupid: Why The US Spends So Much On Health Care, And A Tribute To Uwe Reinhardt"

https://www.healthaffairs.org/doi/10.1377/hlthaff.2018.05144

It would be great if gym memberships could be made free for everyone. I bet it would even be cheaper in the long run to buy an Equinox membership for every American than it would be to do nothing.

Free gym memberships are unlikely to result in higher use. I've had multiple workplaces where gym is free and I've rarely used it, thankfully, I am blessed with a skinny physique and parents who inculcated good food habits. In fact, places which charged for gyms explicitly saw slightly higher usage since some folks logic went, since I am paying for it, I might as well get my money's worth.

American health care plans are starting to offer financial incentives for maintaining fitness.

Which seems a bit like a tragedy of the commons situation.

In that insurance company X is paying me for later life benefits that may be reaped by insurance company Y that I have 40 years from now.

We need to hurry up and get to baseline genetic risks, then directly rebate insured out of a central pot if they exceed their expected fitness metrics.