If your child wants to go into a STEM field, especially engineering, physics or math, taking at least CalcAB in high school is highly advised. It is very difficult for many people to successfully learn Calc 1 in only a semester, in high school you have an entire school year, including a few breaks and plenty of time to bring in a tutor or ask for help from teachers or parents or others.
Engineering physics is calculus based. AP Physics C is calc based and would be another highly advised class for aspiring engineers or physicists.
Our school district allows about 1/3 of students to skip 1st grade math and advance to 2nd grade math. They then combine 4th and 5th grade math, to put them 2 years ahead. With the dawdling caused by taking precalc, they get to CalcBC as seniors. This is actually a pretty popular track (30% of a top 300 USNews HS), some folks drop down to Honors / 1 year advanced at some point if they get overwhelmed. Then there are 3 year ahead folks getting tutored by PhD county education folks on Saturdays and self-studiers.
For an engineer or physicist, that now is all but differential equations, so you could graduate with only some review classes and then Difficult Equations. Those should be easy As.
However, college math is not AP math, it’s harder and faster … so that is why many schools discourage people from skipping too many classes in the progression unless they see that they really have mastered the material. With HS teachers sometimes not having the math background to really teach AB/BC there could be a lot of holes and theory - well high school no longer teaches proofs (nice post above on that) so what do you expect.
So the choice is to work harder in high school or work really hard in college (And not everyone will make it). In the old weed-them-out engineering days, before LEP and selective admissions, that could be 60-70% of the class or well everyone without the 650 math SAT and some HS advanced math.
Without hurting anyone’s feelings, for some people math is a breeze, so you can accelerate and enrich away and they never get lost or behind. If you could bring in college professors and keep stress down, they could be even further ahead.
CalTech or MIT, avg kid could probably have skipped 2 or 3 years of math track and still gotten As.
I am surprised by the GaTech level schools that start most kids in Calc 1 and delay physics, but I think this is a reflection of poor AB/BC teachers and mismatch between math understanding provided by a good to excellent college course vs high school course with mediocre teachers. The well-prepared kids get their 5s (maybe 4s) on BC and just shoot ahead, either taking less classes or taking some 300 level math classes … because they really, really want to.
2-3 hours means you are not ready for Calc AB … a good student maybe an hour a day to get through their problem sets and some additional practice problems. 50 problems do not take 2x 25 problems once you know what you are doing and problems 26-50 are really the college level ones, not 1-25.