...the American government...
What do you think about it? Will that be a problem?
The government will definitely be a problem. It is a problem. It has been a problem. For many things, not just Bitcoin. But what you suggest is not how governments operate.
Just look at how the USSA and the EUSSR are developing into full fledged totalitarian police states. That is how government works.
The Achilles heel of Bitcoin are the exchanges. If government wants to kill Bitcoin, that is where they will hit.