You ignore the possibility that P2P transactions could exist where you are required by your government to run the paying address through something built on top of bitcoin (even just a website)
If people largely comply with that, we've already lost.
The whole point of Bitcoin is that its permissionless and peer to peer.
Well you can send coins on the blockchain in a permissionless way.
That is doable.
Satoshi never said it was a perfect system for interconnecting with the existing financial systems and with government oversight etc.