They are not going to let open weights models with zero restrictions exist dude. They will be regulated like guns, or probably closer to nerve gas or enriched uranium.

Only if you let them.

The government is not going to enforce this, the game theory does not work in their favor.

The SCOTUS has made it exceptionally clear mathematics and software are protected by the First Amendment. The Atomic Energy Act of 1954 tries to make a very narrow exception for nuclear weapons, but

1. The law has never been challenged in court for being unconstitutional, and

2. It doesn't apply to model weights

Any attempt by the government to suppress open models will meet legal challenges on the grounds of (1) or (2).

Congress could amend the act to include model weights, but that won't prevent legal challenges on the grounds of it being unconstitutional (which it is).