In the magazine “We Love Pokémon”, Game Freak's Ken Sugimori commented on the seventh generation of Pokémon.
When asked what the next generation of Pokémon games will be like if such a plan exists, Sugimori commented that they will not add more layers of complexity, but rather revert back to simplicity, in part by using elements found in Pokémon Red and Green. Therefore, there is now speculation that Game Freak may opt for this route in developing Generation VII.
As a side note, not only the number of games, but also the number of Pokémon, moves, abilities, items, etc. increase as each new generation is introduced, to such a degree that is difficult to remember all of them. It is impossible to decrease the amount of Pokémon, and such a move is assumed to be uncalled for, but some fans have claimed that it might be better to significantly organize/trim the moves, abilities, items, etc.
Also, Sugimori thought that other than the content of the game, Pokémon designs could probably be simplified, as well. As an extra, he stated in the same magazine that his favorite Pokémon of all times, even now as of the Pokémon XY series, is still Gengar as in the past.