I know you stated the difference but I still think you’re really confusing the Store and the Exchange
The store uses cash. The exchange uses cubits. You can’t say cash=cubits because that would mean cubits=cash. Since cubits are non transferrable their only real use is to be used in the exchange. You can literally turn parental controls on and never spend a dime in this game outside of the initial purchase.
I’ve played since September and have spent $0 on cubits (only real cash on gleam club which is only a convenience). I have about 1500 plots across all my characters and probably another 15,000+ cubits unspent.
In regards to pay2win argument, boundless is not pay2win. Maybe if we could buy coin, since that would give you access to virtually every item in game. But we can’t. I can however agree with @AeneaGames that you could call boundless payforconvenience. Which I have no problem with, because that money goes towards supporting a game I love and keeping it alive. But there’s literally 0 need to spend real money. If you want to plan out a big build you can just take your time and hoard plots/cubits until you have enough to reserve your area.