One pushback though to your thought experiment is this: if we were suddenly living beneath the iron heel of Tonald Drump or Sosef Jtalin, people will only trade for what they believe has value, (at least at first) I don't think there are enough people in the world who think bitcoin has value to make an economy work.
Bitcoin can resist a dictator, but it can't resist an uninterested market. If we can't find a person willing to trade for it, it won't help us achieve the freedom we all are hoping for--even if nobody can stop us from sending/receiving.
The way I see it there always is someone interested! I mentioned shady people (like drug dealers etc) and political active people. But there are also generally freedom oriented people like current Bitcoiners. There are also probably other countries abroad with demand/supply.
It could even be as simple as someone wanting wanting to buy s*xtoys anonymously. Remember that only 1% in a population of millions already is thousands of people.