Completely agree with you. I'm definitely underqualified to speak of this, as I have no children, but I have a masters degree in pedagogy, started a PhD in pedagogy years ago that I never finished and briefly worked as a teacher, but I've never once in my life saw as little as a proper article with any proof that belief in Santa is in any way beneficial to a child's developement.

Moreover I honestly believe it's detrimental. Such belief often leaves children in poor families disappointed and resentful when they see their friends get much more impressive gifts. On top of that such belief leads to ungrateful and entitled behavior in children as they believe they are owed a present, without understanding the sacrifices their parents have to make to buy this present.

Tldr: Please don't make your kids worship capitalist mascots, if you want them to have a magical childhood just read them a book or spend quality time with them.