The occasion is what people type. A christening, a milestone birthday, a wake or a dinner party carries a tone, a number and a budget, and a page written for that occasion reaches somebody a menu never will.
Numbers change the service entirely. Eight people in a dining room and forty in a garden need different staffing and different equipment, and the guest count is usually right there in the search.
A private chef and a caterer are different purchases. One is an experience for a small group, the other is feeding a crowd, and mixing them on one page confuses both readers.
The peaks are fixed. Christmas entertaining and summer garden parties arrive on the same weeks every year, and the enquiries start well before the season the caterer feels busy.