Underrated comment IMHO. Those "casual"-games look like a gateway drug to gambling addiction to me. They borrow mechanics from games usually found in casinos and it is frightening to see how we let our kids play these games without much thought.
I'm surprised this is even legal in the US, and not caught for app store TOS violations. It seems they've simply replaced the concept of casino chips with virtual currency. They do have some 'gameplay' outside of this but it is not much different from the various frills on video slot machines.
And a lot of these basically copy the 'packs' mechanic from collectible card games, so those would have to be affected too, by any new law.
The trick is to make the user perceive value in whatever digital artifact their are providing. In the eye of the user it then becomes the same as money.
Make the user invest their time into the game. Time is money right? Create fake rewards for arbitrary actions. Then when they are properly hooked, ramp up the difficulty level to a limit where just paying a bit of money would make the game as fun as it was during the evaluation phase.
An ad convincing me to try X energy drink at least results in me getting an energy drink.
Games like this are selling you on a worthless digital item.