How could we revamp the Pokemon games?

What elements or mechanics are absolutely essential to the series? How much could the mechanics be changed before you completely alienate the competitive community? How much would have to be changed in order for lapsed players to come back? Does Pokemon have the potential to be a major competitive game, or is it always going to be a competitive niche? Should Pokemon try to make something that could appeal more to normies and/or hardcore gamers, or should it remain focused on kids and Nintendo fans?

For reference, here's what I think are the most significant mechanical changes in Pokemon so far:
>breeding for IVs
>introduction of Steel and Dark types
>held items
>weather/battlefield conditions
>splitting Special into Sp. Attack and Sp. Defense
>natures
>abilities
>contact and non-contact moves
>double battles
>allowing all types of attacks to be either Special or physical
>characteristics
>Mega evolutions
>Fairy type
>Z-Moves

These have all had significant effects on the way the game is played both single player and competitively (for better or for worse), while leaving the core game relatively unchanged. But consequently, the type of player that plays Pokemon hasn't really changed either.

So what would you do if you were in charge? Would you make more drastic changes in attempt to increase the appeal of the games, or would you make fairly conservative changes to make the competitive scene more balanced or dynamic? Who would you target your game towards?