Here's a reason more students don't succeed at calculus.
And all other math leading up to it.
Especially recommended: dialog between "Salviati" and "Simplicio".
Calculus is the ultimate intellectual creation, invented during the Age of Enlightenment, ubiquitously applicable in theory of almost anything and applicable in determining how to best approximate solutions to a wide variety of real-word solutions.
Advanced Placement (AP) Calculus, which I taught from 1969-2013, is an honest, effective attempt to ensure that students learn well the concepts of calculus. As a "reader" (grader) of AP exams from 2002-2013, I know what it takes for students to succeed on the AP Exam.
And "what it takes" is FAR more than what is suggested by the documents above. Those are merely "cram sheets" for the exam. And they're somewhat incomplete, though pretty good for a (goal of) one-page document.
Neither the format nor the idea is mine. I don't know who "did it first", but every idea/keystroke is mine.