>>27325021In the Gen 7 games, there will be a feature called hyper training that allows you to change the IV's of a pokemon using a special item. The requirement to use this item is that your pokemon must be at lvl100.
I say IV breeding is more efficient because it takes less time(less than an hour for me to get a perfect 5iv in my experience), while it takes hours or even a whole day just to grind all the way to 100.
Now, would you rather go through tedious level grinding for every single mon? Or breed which will most likely take less time?