This is the curse of Home Depot, which doesn't stock much, if any, metric. I was recently in a Home Depot where an Asian woman was trying to get some fasteners to repair some piece of metric restaurant equipment, and wasn't aware how backwards the US is on metric standardization.
The US needs to go hard metric. That means metric fasteners and components. The rest of the world does not have inch tools. This hurts exports. The 95% of the population that can't use any tool beyond a screwdriver can still talk of inches and miles, but physical stuff needs to go metric. Autos, aircraft, and DoD switched decades ago. It's mainly building components that are still inch.