The Affordable Care Act introduced the newer perverse incentive of insurance companies tolerating higher prices. Because if you can only pay your execs bonuses based on 20% of your total spend, insurance companies can pay execs more if the underlying claims they're paying cost more. 20% of a $1,000 MRI isn't as juicy to your C levels as 20% of a $10,000 MRI.
All insurance companies, all of them are corrupt. The whole system needs to be burnt down. PPOs are the worst, I wish HMOs were the norm, but that won't fix everything.
Further reading: https://www.investopedia.com/terms/m/medical-cost-ratio.asp