>>54439100Speaking as someone who's reached Temtem's equivalent of Master Ball rank.
I will start off by saying that Temtem's mechanics aren't 1:1 of Pokemon, a lot of things are different that may exaggerate the issue of stamina, such as stat boosts remaining upon swap-out and that the format is doubles. Numbers may also play a role (i.e. lower stamina may make a difference) but overall battles are very, very fast paced and snowball-y and heavily favors those with a winning opening. Tanks become far more broken than what they ought to be as they have high stamina pools and having stamina as a mechanic in general makes it far more difficult to wall break through them because they're designed to soak up damage and thus causing you to expend more stamina than usual. It also gives a lot of power to swapping out in the sense that not predicting correctly ends up being severely punishing as every bit of stamina is invaluable; not having enough can damage you and rob you of a whole turn, which brutalizes momentum despite how hard it already is to get going without an advantageous opening into the match as mentioned before. On top of this, it puts a lot of emphasis on type match-ups when it's already difficult as is to survive in a disadvantageous situation due to it; you could simple lose a match from type matchup alone which eliminates a lot of skilled gameplay revolving around triumphing through that disadvantage.
All n' all, stamina just simply isn't necessary. It adds a lot more complex thought, but it also dumbs down a lot of elements that already existed and can make it feel impossible to play without just simply having a better starting hand or meta-abusing particular gimmicks such as Deceit Aura which is the Trick Room variant of Drought/Surges. It also makes it hard to play casually, as stamina HAS to be on your mind at all times. It isn't better or worse than PP, it's just different and as such comes with its own set of problems just like PP does.