It might be annoying if you already know the content. Frame it for the least common denominator (pun intended) - the person who has the time and needs the repetition to pick up a concept.

While it depends entirely on personal opinion, I believe that it helps significantly. It helps build up the problem/solution from the ground up and he goes through each step out loud to help a student understand. I get that some people hate it and think it is so childish for such simple steps. For other people, it helps a lot. Learning on KA works best if started aat a young age and done consistently (you get used to the style and you learn everything from the ground up).

OTOH creating neural connections takes time. It's a real distance. Small for us, but great for the cells. That's why explaining difficult concepts too fast, while cool for people getting things instantly, is not good for general population.

I originally learned linear algebra from Gilbert Strang's OCW videos, and I was only able to stick with them by 2x'ing the playback rate; at this point, hearing Strang at his normal speaking rate sounds to me like hearing him after a Robitussin bender.

This is exactly what my kid said about why he doesn’t like Kahn academy.