So I am wondering about a question many others probably have. We all know that the mechanics of pull ups and chin ups are somewhat, but not very, similar, and we know chin ups activate biceps more, but in the end, for back, bicep, abdominal, and forearm development, which one is more beneficial?
In answer to your title question, no. They both involve all of the muscles listed above. A chin-up focuses a bit more on the biceps whilst pull-ups distribute more effort across the back. Changing the width of your grip will focus on different parts of your back. But in the end, your body is doing the same amount of work over all of those muscles you listed. You can vary them depending on which parts you prefer to focus on.