For whatever reason, I had cause to do a Google search to which countries are not using Metric units as standard/default, especially in everyday life. Apparently, it's only three countries in the entire world. Myanmar, Liberia and, of course, the USA. Both Liberia and Mynamar are currently in the process of converting.
There's a still one or two outliers who have mainly metricated but for various reasons still use some non-metric units, eg the UK still using pints for beer and miles and miles per hour on the roads.
Sometime very soon, only USA will be non-metric. Big enough not to care? Maybe, but I bet it's already an issue with some imports. I suspect they will be forced into metrication by the back door. It took the UK a long time (and in some case still is) in that some products, while measured in millimeters, are just conversion from the inches size. Most food products seem to have transitioned away from Oz and pints to grammes and Litres now, no more 454ml of milk etc.
I'd expect something like NASA is actually metric and they only convert to Imperial for press releases aimed at the local population.