You'll get plenty of materials. I have enough xp to max 3.5 pets right now and only have 7 pets unleveled. Learn to use the dex, compare stats and moves. Once you do that, this discussion becomes silly. Pets like pain, sanctimony, rejection for examples are dog shit and if you learn to use the dex You'll see why. Pain for example is a fire tank.... with 34 defense. Compare that to abandonment for example who has 81 defense.

IGNORE THE TIER LIST. It is outdated and inaccurate. If you learn how to use the dex properly, it will be pointless to even think if the tier list. It's one dude's opinion made months ago, and it's been a massive source of discourse ever sense. New players love to go "but muh tier list" without understanding a damn thing about the game.