Imagine it being 2020 and not using the metric system.
Sure the power of ten thing is convenient, but really that is just sticking to one unit and adding a prefix. You could call "thousandths of an inch" a "milli-inch" and it'd be about the same.
Fahrenheit is absolutely a more useful human-scale measurement than Celcius. The boiling point of water is mostly irrelevant to everyday life. At that point you might as well just do things in Kelvin.
Perhaps the usefulness of Fahrenheit is only a thing when you live in a continental climate though.
100F is about as hot as it's going to get here in Iowa.
Similarly, 0F means that it's the depths of winter. Anything above 0F is pretty manageable. When you start going below 0F you're getting into "real cold" territory.
Point being, Fahrenheit is a scale that matches well to the climate extremes (at least around here), which I think is a significant advantage for it.
As to the rest of it, a meter is basically a yard. A liter is basically a quart. A kilogram is just two pounds. Not really that difficult.