The United States is one of three countries in the world not using the metric system. The other two are Liberia and Myanmar. Every scientific institution, every pharmaceutical label, every international trade agreement already operates in metric. The resistance is cultural inertia, not practicality.
A federally funded transition program (updated signage, revised textbooks, a ten-year runway) would bring the US in line with the rest of the world. The cost is real but finite. The ongoing cost of operating in two measurement systems simultaneously is also real, and it compounds indefinitely.
It also makes a lot of math class considerably easier. That alone is worth something.