As someone who regularly deals with metric and American (not British) imperial measurements, they both make sense in different circumstances.
American imperial relates well to what we see.
Metric makes math easier.
E.g.
100F is really hot — 0 F is really cold 100C is death — 0C means wear a jacket
1 mm is tiny — 1 cm is really short — 1 m is long — 1 km is kinda far (nobody really uses dm)
1 inch is short — 1 foot is kinda long — 1 yard is long — 1 mile is far away
Etc.
There are easy ways to convert between the two systems in some cases, though.
Km and miles:
Fibonacci sequence: any 2 subsequent numbers are a close approximation, with miles=lower number, km= upper number
Inches and cm:
1 inch = 2.54 cm (exact) So, 4 inches = (about) 10 cm or 100 mm
Kg and lb:
2.20462 lb = (approximately) 1 kg
Double number of kg, move decimal left, add the numbers, and you have pounds.
There are other easy (mental math) conversions between the two systems.
Note: I do not personally prefer either system in general— just have to deal with both regularly for work, and have noticed advantages to both.