>It was objectively better system
No, it isn't, and I've already outlined the reasons why.
>Reducing SI adoption to “gunpoint”
Is what actually happens. The French pushed it through their Revolution, the Soviets did it in '25, the PRC in '59.
Interestingly, a good chunk of the existing Chinese measurements were metric themselves for a while: simply imposing a new order was the objective. Thus always to modernists.