Over here we don't do santaclaus but we have sinterklaas. Don't ask about the specifics but it boils down to the same theme. I loved that my parents "lied" to me about it because it was freaking magical for 5 years when i discovered the plot by myself.
You may not approve with lying but you may want to think about it before you ruin what could have been a magical time for a while. It is clear that not everybody experiences this the same way you did or else we could have gotten rid of all of it by now. There's more to it than just a lie.