I feel like XY were great, but they lacked staying power.

I mean the online is wonderful and all, but with little postgame, no other mons to catch other than friend safari, which, while being incredibly convenient, wasn't the safari zone I knew and loved.
Combine that with no transfer system for 2 months so there is no way to get/train the unobtainable ones, means there's less team building/breeding I can do.

I guess the game just burned out faster than I expected it to.