Yes they can. Very easily. People put time and effort into breeding and raising a pokemon and then stop using it when it stops being useful on their teams all the time.
These games are becoming easier and easier just because "oh no, we can't make kids THINK or put in too much time! If things become too much of a hassle for them they'll just buy phone games!"
I hate when they make these games easier like this. It's pointless hand-holding because they think their audience are a bunch of idiots with no patience.
This is the kind of stuff that led to us getting no Battle Frontier in ORAS.
It's not supposed to be challenging, it's supposed to be time-consuming. It's something you put effort into and get rewarded. Why should I put in any effort now if no one else is going to?