Nitro, Shop, and Quests. What are these even?
Even their changelog page is wtf (https://discord.com/tags/changelog)
Shop is where they sell customization stuff.
Quests let you earn currency you can use to buy customization stuff or nitro instead of real money.
I don't think there's a significantly better way to do whatever they are doing, and I don't see anything particularly objectionable about any of it.
Shop is where you can buy additional customizations.
Quests get you exclusive unlocks for various games.