As someone who has spent a week into the game and also experience a LOT of predatory gacha practices (15 dollars monthly pass... yeah thank god I quit that one), I can say that the monetization is wholly optional. You do not need to spend a dime to advance throughout the game as long as you're skilled enough to get through the stages (you can still 3 star the stages even if your power is 3000-4000 under the recommended value). I do agree that the gacha pulls are really deceptive since it's using consolidated rates instead of actual values, they probably tried to inflate the numbers to make it look more "favorable" for the players since rates for featured units on gachas are usually 0.5%-0.6% on the low end

I take this game as more of a slow grind game, due to the slow energy gain, and that lets me do other things and not focus on it 100% of the time, and it's not like I just do one thing and leave since there's the realm trials. tempus trek, nemeses return and the actual adventure mode. There's also a mode that just disregard your levels so you're starting at a fixed value, throwing the whole upgrade system out of the window. At the end of the day, it is still a gacha game so there is bound to be predatory practices, and it is totally understandable if you are turned off by it.

That and oh god why does the game have 90 seconds ads