For the most part, when the media talks about "math" in primary and lower secondary school we're talking about arithmetic. I remember learning Calculus as a teenager, and it was confusing and not intuitive, but once I got it there was very little more I needed to do. That was a completely different experience compared to multiplication, where I had to drill with flash cards before I had enough of the fundamentals in order to do arbitrarily large multiplication problems, and later it proved to be a vital prerequisite for long division.
Not everything stuck with me, despite practice. I'm really slow at polynomial division, I don't have the basic process down in my head and I use it so rarely that I tend to have forgotten steps when I eventually do need to do it.
I think by the time someone enters high school, they ought to have a basic skill in arithmetic. They don't have to be the fastest at it, but it's going to hold them back in the sciences if not mathematics.
Do you want a nurse that can't add 0.15 mL and 0.35 mL ? Processes in a hospital avoid putting people in the situation of doing arithmetic on the spot, but it tends to happen and people screw it up.