I think linear algebra is a much more valuable and general-purpose math tool. I'm not sure how feasible it would be to teach linear algebra topics "properly" to high schoolers, but even a half-assed linear algebra would be more useful than calculus.
The connections to geometry, general systems thinking, formal math methods, and countless applications of linear algebra are just the kind of thing students need to get them interested in learning more math.
Anyone interested in LA an its applications should check out my upcoming book, the No bullshit guide to linear algebra availale on pre-order here https://gum.co/noBSLA (it's almost finished; just beefing up the problem sections).
They taught me about matrices and vectors and common matrix/vector operatoins in pre-calculus and even earlier in a shitty public school.
Calculus needs to happen in high school so that people are more prepared to take it again in college. For me, calculus 2 was the hardest class in college. This is coming from someone who went to a math grad school.
Some people need to study way more for calculus than for any other class in high school or college.
LA wouldn't be any harder to teach than Calculus. In fact, if you wanted to teach proof based math that isn't Geometry, it's probably the easiest subject area.
I don't think you can get rid of Calc in HS though. It's just too useful. I think room can be made for both subjects, though.
The connections to geometry, general systems thinking, formal math methods, and countless applications of linear algebra are just the kind of thing students need to get them interested in learning more math.
Anyone interested in LA an its applications should check out my upcoming book, the No bullshit guide to linear algebra availale on pre-order here https://gum.co/noBSLA (it's almost finished; just beefing up the problem sections).