This is probably due to a selection effect. Physics C almost certainly attracts a much stronger group of students than physics 1 does, in terms of learning physics. Note that something similar can be seen between calculus BC (48.4% score 5), calculus AB (24.6% score 5), and statistics (14.3% score 5).
In any case, does the OP need to take any AP level physics in high school? Looks like a regular high school physics course be sufficient for the OP to get a basic knowledge of physics and be ready to take physics in college (although the OP probably won’t)?
Indirectly yes, in that a lot more kids took AP Physics 1 than in the past took AP Physics B because a lot of schools (based on College Board’s recommendation) got rid of Physics Honors. So there were probably a lot of kids that should not have been in those classes. Also, (and probably more importantly), it was the first year so there were a lot of growing pains. Teachers had to figure out what to teach without a lot to work with–nmuch out there for guidance and no prior exams questions to prep their students with.
But agreed, while an Honors (if it’s still offered at the OP’s school) or AP level would obviously look better, even a regular physics class would be better than nothing!
Harder in terms of probability but not ability. Similar thing for Math1 and Math2 in SAT2.
It’s not a dealbreaker in the admissions process that you haven’t taken physics. That being said, you should probably take it if you have the opportunity since it’s considered standard. It’s also a fantastic subject.