What do you imagine the US could do with its weapons cache to demand global compliance? Even extremely authoritarian governments that have tried to stamp out crypto usage internally have been unsuccessful, so it's not like the USG could just lean on other governments to demand compliance.
I don't think the person you were replying to was saying that it was going to take over as the primary reserve currency, do you?
So the US controls those international settlement rails, what does it do with that power to control BTC? Like I said, they can lean on governments, but those governments don't really have the power to ban it internally, so what can it really do with that leverage?