Why do most CS videos on YouTube have to be explained by a person with a bad mic?

Don't forget the Indian accent please

Because they are under the mistaken impression that they have enough experience and knowledge to teach a complex subject with a few short video tutorials.

They couldn't be more wrong.

Richard Buckland's COMP1917 lectures from UNSW, and Ableson and Sussman's MIT lectures are the only ones I'd ever recommend. Literally everything else is worthless, subpar dreck.