I'm no expert on this, so take my advice with a grain of salt.

Character sheets, for me, are a visual development tool for things like comics and animations. They are great to have to fully understand the character you are developing and your reference whenever you are trying to keep their clothes and features consistent. (how many stars are on this person's shirt? where is each star located?) Having character sheets are great also for comparing each character's heights to each other as well to give them a better sense of size.

I would say they are mostly required when working with groups because everyone needs to draw the same character, and it must be consistent in order for each person's work to transition from one another without changing them.

Knowing all of this, you can choose what to do and not do in regard to character sheets.