Knowing how fractions work is pretty important in algebra and other more advanced math courses. I’ve used it a lot, but then I’ve occasionally been teaching math. Mechanics and carpenters also find knowledge of fractions useful.
But, I do get your point. We also had to learn how many pecks were in a bushel and other bits of math that are now obsolete in the modern day.
On the other hand when I first started teaching in the late 60s, ‘Modern Math’ was the fad. I had to try and teach poor 4th and 5th graders how to calculate in base 6. The NCTM thought this would get kids to see patterns in the math they would use every day. They didn’t.
I watch “This Old House” on Pluto tv and the guys use math all the time to figure everything.