At the rate that providers are dropping their practices, the networks will probably hit 30% of available providers solely through attrition; the ones who signed up are the ones who think they can make a go of it, so they’re more likely to hang in, while the non-signers don’t want any part of it and are more likely to hang it up over the hassle of joining the system.
Eventually the fines will increase to the point of the premium payment. Pay an outrageous premium or outrageous fine.