Funny, the ones (aka some of the best players) who say coins are worthless have trillions, billions, hundreds of millions. Coins are necessary to wager in the COIN rooms. Coins are necessary to upgrade apparel. In fact it takes several million coins to achieve level 10 apparel x 5.
If you don't play the coin rooms nor care about apparel or upgrading apparel... then coins are worthless.
I've been working on apparel for about 7 months. Switching paths along the way, which costs extra coins, and I'm still months from getting what I want to wear to level 10.
Yes, I have the coins to pay all future apparel upgrades, but still have to earn the apparel. And why is when that ghost "platinum box" shows up, it's never carrying what I need? lol