Mob programming is such an asinine concept to me. It's like all the people saying holotropic breathwork cures cancer. It's just developer mysticism. There is no amount of himing and hawing that would get me to believe treating one guy, capable of his own expression, as a code-input robot while developers around him bark commands at him is actually productive. Each line of code is so expensive and the probability of any one of the people barking the code remembering how something works is pretty low. There is significant evidence the action of typing/writing something produces better memory.

It works when you're helping a junior. It's insulting to anyone else. Part of our jobs as programmers is to be able to tease apart another developers mental model and learn the abstraction. If you cannot do this the codebase is either unsaveable or you are. The only codebases I have been unable to untangle in my long career have been either written by contractors or by a pseudo-intellectual moron developer that believes they are the second coming of Turing. Everyone else's code is usually able to be parsed with some patience and a debugger for more complicated tasks. I even gasp use pencil and paper to keep track of code flow often.