In movie and television universes where Santa exists but parents don’t believe, the question is often raised “Are parents surprised when their children find presents the parents didn’t buy?”
The answer to this is disturbing. Santa is a magical entity; when he delivers presents to children, he also delivers false memories to parents at the same time. Parents who did not buy that bicycle or dollhouse suddenly remember having done so - with all the associated memories of long lines and laborious assembly. In the Santa-verses, the most fortunate adults are those few who still believe (like Iggy’s father in the Year without a Santa Claus); they can be secure in their memories. Everyone else is unknowingly living a lie.