Disney Speedstorm is now available in Early Access
Get a Founder's Pack to be able to participate.
There aren't a whole lot of really good Mario Kart 8 Deluxe alternatives available for other formats, but hopefully Disney Speedstorm has the potential to become one. And it might even get a big audience on Switch as it offers two things Mario's racing game doesn't: Disney characters and free-to-play.
Unfortunately, the latter is only partly true. While Disney Speedstorm will indeed be free-to-play when released later this year, the Early Access version that launched yesterday is only available if you get a Founder's Pack. While considering if this is worth your money, check out the launch trailer to both see some new gameplay and all the different Founder's Pack editions.