It's closer to Crash Team Racing than Mario Kart but ya its in a very good spot in Early Access atm despite the smaller player base. Luckily there's so much offline content to do now. I heard that it supports 8 player split screen but I haven't tried yet.
The only gripe I have with the game is the weapons system. Everything locks on which sucks since there's no rral defensive options like in Mario Kart and you can't lay down traps to protect yourself in first place either.
It's closer to a do whatever you want game but there are goals to work towards. It's like a super small scope no mans sky with no combat. Super chill and casual.
You're missing out on the fact that the game isn't actually complete. It's labled as a 1.0 release only because all the classes are now out. The full campaign still isn't done and is missing several chapters. The devs themselves mention this.
Theres an ifixit video on it under 3min. They should also have some written guides on their website which should help a lot.