As a toolmaker-machinist, I had to regularly work in inches or millimeters, and with a cheap
hand held calculator I could effortless convert one unit to another. So I can in that sense say, neither system is better or worse, they are just different. Take away my calculator, then the metric system is way easier because in operates on switching decimal places in base 10.
But for some one like an auto mechanic having two systems is a curse, on one hand they can interchangeably use a 13 mm wrench or a 1/2 inch wrench, but most wrenches of other sizes won't interchange. So the mechanic is buying two sets of expensive wrenches and sockets when only one would due if we had only one universal worldwide measurement system.
But the biggest stupidity on this thread is this crap that if I weigh 150 pounds I would weigh 10.71428571 stones. The point is + or minus 0.00000001 stones is only only a milligram. The amount of air in your lungs makes you weight vary more than that. Not to mention the fact there are few if any measuring devices on the planet that will measure your weight as precisely as that. Which is why we have to understand the use significant figures of measurement in our statements. How precisely can we put a valid number on things in the real world.