I am not particular to online classes.
As an American Heart Association instructor, I see students taking classes with instructors are more fluid and can apply the necessary skills in a more coherent, fluent fashion.
The American Heart Association also offers online classes, but to provide AHA cards for these students, the students have to demonstrate their skills to an instructor. About 3 out of 4 students taking online classes I test, show to me they need help. At first they would stop after each little skill for me to tell them they have mastered the skill. They do not show continuity.
In other words, students that I teach the class, as well as other instructors, go in an "1,2,3,4,5,6,7,8" step.
Students that I ask to demonstrate the skills go in an "1 pause, 2 pause, 3 pause, 4 pause, 5 pause, 6 pause, 7 pause, 8 pause." Each pause expecting me to say "it was good, next step." I have to deprogram them telling "do not pause, go into the next step in a fluid motion." Or "you are taking too much time to do that skill." Etc.
I am afraid those students using online classes with no instructors may be learning the skills individually may be having the same problem. That is probably why state Health Departments specify that BLS classes have to be taught by instructors to have valid cards for hospitals and state summer camps.