IMO metric also allows you to reason about things in your head more easily because doing base-10 calculations in your head is doable.

For example, “Each 1m section of a pipeline contains 20L of oil. The goal is to empty a 200 km section of pipe into trucks. If each truck can handle 20 tonnes of oil, how many trucks would be needed?” In metric that calculation is 20 * 1000 * 200 = 4 million L. 20 tonnes is approx 20,000 L since 1L of water is 1kg, so it’s going to be at least within an order of magnitude of that for oil. 4M / 20k = 200.

With US customary units it would be "Each 1 foot section of a pipeline contains 1.5 gallons of oil. The goal is to empty a 100 mile section of pipe into trucks. If each can handle 20 tons of oil, how many trucks will be needed? To handle that calculation you’ll have to convert feet to miles. Gallons to pounds, pounds to tons, etc. You can do it on paper, but all those weird conversions add massively to the difficulty.