Best answer: Though you can play against bots that appear to be AI versions of other players' accounts, you can't play true multiplayer races in Mario Kart Tour ... at least not yet. It's an unusual departure for a Mario Kart game, because, let's face it, racing against other players is usually most of the fun. However, Nintendo has hinted that multiplayer may come to the game in a future update.

What Mario Kart Tour does to make it look like you're playing multiplayer

When you get ready to start a race in Mario Kart Tour, it sure seems as though you're about to go head to head with other live players. The game reinforces the illusion of multiplayer by using screen names that appear to be ones humans might use. Plus, it has multiple versions of the same player or kart, as often happens when you play other Mario Kart games.

Alas, "illusion" is the keyword here. Nintendo is doing its best to make it feel like you're competing in real-time PvP when you're just going up against some convincing (most of the time, anyway) bots. Why did the company do this? Presumably to avoid having the server issues that multiplayer might cause, as Nintendo hasn't really done a mobile game to date that has required that kind of tech.

But Nintendo has at least thought about multiplayer

This might be a bit premature, but Nintendo does seem to have a road map for Mario Kart Tour that includes live multiplayer. If you go to the game's main menu screen, there's a 'Multiplayer' icon with a very peppy "Inbound!" message. Tapping on it gives you this message: