Which feature would you like to see in Pokemon Go?

I think its fine to just have the IV's.

Niantic should offer a way to increase the IV's of a choosen Pokemon (for example via Buddy walking say each 100 km etc.).

They should remove IV's.

There should be a way to aquire Efford values. For example battling/walking with a Pokemon raises its EV (the cp of each Pokemon could be capped at 4000 cp so no one can go beyond this and have ridiculous cp).

I would love it when I could make my favorite Pokemon somehow viable (putting a lot efford on this specifc Pokemon like Buddy walking/battling etc.) so I can use them and do not need to stick to the meta. For example those Pokemon could be powered up "beyond" their "max cp" etc. (maybe with a max cap for all at 4000 cp).

Natures should be added to Pokemon to make each one more unique.