I'm not at all saying you can't build things using metric. I'm saying that there are certain advantages to a system that's base 12. the same reason as boards are sold in 16 foot lengths rather than 20 foot lengths. .
Mostly what I'm trying to argue against is the idea that switching to metric will be universally equally good for everybody. Which isn't exactly true everything is always more complex than that. And again they're definitely certain advantages for using Imperial, a quick look at some online forums reveals that a lot of the English-speaking world professional carpenters use Imperial rather than metric even though those countries have adopted metric probably long before those carpenters were born. Now is there some aspect of inertia in the trades that's responsible for that, almost certainly some part of that is due to that but I don't think you could say all of it is at least not with any real degree of confidence.