Its a matter of perspective. Billions of people believe in God. I may be wrong but I don't think anybody believes in wood sprites or mermaids. I don't know that Sprite exists but I prefer 7 Up.
Indeed, they believe in about 275 very different Gods. And there has scarcely ever been a tribe of humans who did not consider themselves The Chosen People. How does that work? Logical deduction concludes that they cannot all be right, but they can all be wrong. You are wrong. There are people who believe in almost anything. But that is just as irrelevant as billions of believers in god. I agree that something as long-lasting and pervasive as human belief in a diety is significant. It does not prove the existence of a diety, but it does demonstrate that paranormal concepts are part of the human psyche. Perhaps an important part.
The major monotheistic religions all believe in the same God even if they call Him by different names and have different interpretations of what He expects and commands them to do. Nothing can ever prove or disprove the existence of any deity. The fact that almost every culture in the history of humanity has some kind of belief system does seem to indicate if not prove that the want to believe in something bigger than the individual is universal. If anybody does really believe in wood sprites its probably @LaSalleAve