The fears you outlined are unnecessarily anxiety-inducing in my view. In order to feel at ease all you need to do is look to Venezuela. The market situation you describe is happening there right now. Their market is being ravaged by internal (and external U.S.) policies. Their hand has been forced, and Venezuelans are adopting cryptocurrency at a high rate.
The same thing will happen here in the long-term. Fiat will ultimately crash and instead of laying down and dying, the market will seek shelter in crypto. I don't see any circumstances where businesses will lay down and die in order to refuse taking crypto in the land of the "free."
Of course there is one fatal situation where this could happen, but if we can stave off global cataclysm and martial law long enough, I don't think we need to worry.