Any reward presentation, assume there is a loot table behind it. You see 4 cards on the screen, but there may as well be 1 big slot lever; cuz no matter where you tap you're doing a single prng rand and getting what the loot table says.
The loot tables aren't at all what you expect, they skew heavily towards 'booby' prizes cuz that makes it easy to predict your progression. The screen might show you 4 cool things you can get alongside 1 lame prize, implying 20% odds; but the sum odds of those 4 cool things will be <5% and most of the time you're getting a predictable lame drip.
The one thing working in your favor is a 'pity' counter. Every time you get a booby prize the pity counter goes up and leads to another rand call. If you succeed at beating the pity counter, it'll give you a good prize and reset the pity counter. The net effect is that I can program the reward stream such that you're guaranteed a good item every 50 pulls or whatever. Some games are just straight with you about this, others aren't.
During the onboarding flow, which could be designed to last months depending on the game's age, your entire reward schedule will be painstakingly controlled down to the coin. Not a single rand call in sight.
My advice is to play these games if you understand all this and have friends to play it with. They've got good hobby value, on a per dollar basis. I mean, have you seen the cost of golf? If you don't get how the monetization works, and you're alone, there's healthier hobbies to spend your money on.