Not it's not. I'm very familiar with the English system. Speak to some actual healthcare professionals from outside the US and you'll get a clearer picture.
They get care when they need it, without being handed a bill, and the size of the money going into the system is actually smaller because they're not paying for profits and wages for health insurers.
They get cheaper drugs because the government negotiates those contracts on behalf of the patients. If they lose access to cheap drugs from the US, they'll award those contracts to foreign pharmaceuticals who CAN keep their prices low. Maybe that will suck for us from a US wealth generation perspective, but it won't destabilize their systems by any means; that's fantasy on your part.