People need to realize that for games like this, the entire point is making us frustrated. Can you imagine how many upgrades people made to Appo today in frustration, hoping that one more gear or relic level will get them through the tier they just lost? People buying resources (and using up resources so they have to buy more later) is literally what makes CG money.
I'm not defending it. In fact, I think this game model is downright predatory. But that's the nature of this game. CG has always done their best to make players frustrated enough to spend but not frustrated enough to quit. (And they end up overshooting and accidentally crossing that line a lot, at least with some players. Or they calculate that the new spending will more than offset those who quit.)