>>35766663IVs fail to do that because 99% of the time you just want 31 IVs in everything so all pokemon end up being fundamentally the same at a competitive level.
IVs are a bad mechanic and always have been. Stat XP was replaced by Effort Values in gen 3 which was a great change that exchanged mindless grind for customization.
I maintain that the EV system should be made fully transparent and that you should be able to set each individual stat to increase, decrease, or stay the same. I wish they'd merge abilities into a talent system of sorts, where every 10 levels or so you get to pick a perk. Your 'ability' would be the intrinsic, lv0 perk.
Some talents could be type based, others egg group based, others locked to particular species (including signature abilities and ones that would be automatically broken for non-shitmons like huge/pure power). Doing it on this basis would give them a way to distinguish the types from one another, like how rock has been envisioned as a defensive type from the start, but in practice has mostly been used as an offensive type because of the prominence of water. Maybe they can take a talent where they're only 1.5x weak to water, but 2.5x weak to grass. Stuff that wouldn't really need to come into play during the main story but would make battling at a competitive level more interesting.