The Many Times The US Tried To Go Metric

Haven't watched the video, but as someone who works in industry in the US I think the consumer side of a metric switch is the lowest barrier to entry. A much bigger hurdle is the fact that almost all of our raw industrial inputs are built on the imperial system. Need to buy raw plate or bar stock to have something built? It's sized in imperial. And if you want to source metric you're either going to have to pay more for it or look outside the US. And after that raw stock is purchased and you send it to a machine shop that machine shop is almost certainly using exclusively imperial tooling and measurement equipment. You can do the fake metric thing that some companies do where you dual dimension all of your drawings, but those companies will usually still design to imperial so their parts can be fabricated in the US.

I'm absolutely not opposed to a switch to metric. I still perform most of my calculations in metric and then convert to imperial just for ease and because that's how I was taught in school. But it's certainly much more difficult than just deciding one day that we're all going to switch.