I remember at that age understanding that ads are not truthful at a deep level and filtering them. I find it's much harder for me now. Everything seems like an ad now a days and I may not believe the message but having the money to pay for so many ads on expensive platforms gives me a different message. If a company can afford a superbowl ad it gives me the impression the product has resources behind it and I can assign a level of trust.
Both make a list of the naughty and nice boys and girls. One substitutes brimstone for coal, nebulous "eternal happiness" for toys, but they seem pretty similar to me.
I think that's excessively reductive and there are other differences, like incontrovertible proof there is no Santa (as opposed to merely a lack of evidence), the fact that Santa often has the exact same handwriting as Mom and Dad, the fact that no supernatural powers are attributed to him and yet he would need them to do what he supposedly does, etc. Besides that a debate about Christian apologetics kind of takes us away from the point I was making.
Santa Claus is Saint Nicholas, in order to become a Saint you have to performed miracles in the eyes of the Catholic church. He certainly does have super power, at least the ability to resurrect childre, if he is real.
I think we can safely say that Santa Claus the children's character is almost completely divorced from the guy who punched Arius at the Council of Nicea.
Both are fictional, believed by a large demographic and don't instantly signal insanity, just gullibility.
Gullibility, which is what we were talking and why advertising to children is bad. If we started teaching our kids to do things like try to test for Santa they would be more likely to come to correct answers for the rest of their lives, and in general be less gullible.
Kids are better at filtering in some ways.