Prices get complained about more, because they are perceived as unfairly high. Image is much more important inside the berm than outside. In short, it's a challenging job. That someone is the Lead. I haven't even touched upon the Lead's role as a sort of go-between representing the CM's to the managers and vice versa.
Leads do a lot.
Yet, Disneyland for a time in the 1990s took away Attractions Leads. The idea was to trim the most expensive hourly positions, and thus save money. That made for dangerous conditions in some cases at the rides, breaks not being given out on time, and people in general not caring about efficiency. Unions were mad, guests were mad, and Cast Members were mad. Leads, you see, are necessary.