That's simply not how the system works. For the most part, medical insurers no longer provide much real "insurance" in the sense of bearing risk. Instead they mostly act as administrators for employer self-funded health plans. Since insurers are subject to an 85% minimum medical loss ratio, every paid claim is actually a gain because they get to take up to 15% from a larger revenue stream. The majority of the pressure to tighten coverage rules actually comes from those large employers since they're the ones ultimately paying the bills.

https://www.cms.gov/marketplace/private-health-insurance/med...

If anyone wants to see real reform then eliminating employer sponsored health plans is one potential way to get the incentives more properly aligned.