https://www.cnet.com/news/mario-kart-mobile-nintendo-march-2019-tour/

No, you haven't, because there is no Mario Kart on iOS or Android. That will change though, as Nintendo Wednesday made a big announcement via Twitter: Mario Kart is coming to mobile platforms in the form of Mario Kart Tour.

Not much information on the game was announced, though Nintendo did note that it'd hit your phones and tablets by the end of March 2019.