I would disagree as to them being in the same category. Most of those things are falsifiable (dwarfism exists
). God existing is either a fundamental fact about the universe, or it isn't. In many ways, it's not a discrete specific structured thing we can study. People usually have some basis for believing in God. '2 billion people can't be wrong' is a terrible way to argue, since it could be said of every other religion, with differing numbers, but 'two billion people currently believe in the modern age in this thing' is still an argument for not dismissing it as on the level of fairy tales and fictional literary characters. Many of them are very intelligent people. Most of them have arguments that they believe are strong enough to justify belief in the existence of God.
How many children are there out there who believe in Santa Claus?
Ah, but the difference there is that Santa, despite being based on known historical figures, is a known constructed lie made by adults who define Santa in terms of a set of claims, which will unravel with a little critical thinking. As pointed out by Roleplaygeek above, when a god is defined as a specific god claims about it can be tested, inevitably showing the claims to be flawed - the same as Santa. Olympus can be climbed, and Zeus and his gang were not up there. The result of this is that due to social Darwinism the faiths in god that remain extant in the world today are either non-theistic (like Buddhism and Taoism, so no god claims exist to unravel), or handily contain a god "claimed/defined" as so far outside the human experience one could never hope to interact with it regardless of claims in its holy text (Abrahamic faiths, Hinduism and so on). This in itself is to me a bizarre claim for a faith to make, as in said holy texts gods were dicking around with humanity all the time, which seems juxtaposed to the whole "out there but we can't get at them" reasoning. 1bn or so kids hold a belief in Santa, because they are told to. There is nothing to base that belief on save for the mythos they are fed. Does the same apply to those who hold a belief in god? I say yes, to a certain extent. For the most part, they are told in their youth of a particular god, and build up an argument around it while they have the knowledge in order to justify it. An almost statistically insignificant number of people end up switching faiths as a result of examining religious ideas and arguments about gods and their nature compared to those who simply reinforce what they already thought about gods, which to me suggests a certain amount of preclusion.
If we defined Santa as some kind of pan-dimensional everywhere omni-gift giver instead of a fat guy in a suit, the myth may be more pervasive, perhaps