Depends on the game. Definitely if it's going to split your party or make you use one specific character...
It's also possible to have different kinds of experience (not sure if all of the tales games did it? Tales of Symphonia did) where all the characters got EXP. but only using moves actively in battle gave you acccess to stronger moves.
fisheries said:
At least the grind fits in Pokemon though, for the setting, you are meant to be training them. Pokemon also has plenty of opportunities to practice clearing trash, even at higher levels, but I wouldn't regard the fact that a large number of your Pokemon are going to end up underlevelled and then underused, if at all, simply due to not being good enough for their level, or getting outlevelled as a good element of design.
Part of Pokemon is that everyone's experience will be different (if only slightly) and their pokemon individuals.
I might catch the first Pidgey I see and name it Prunelle and keep it with me to the journey all the way to the elite four. Someone else might not catch pidgeys at all, or only for a pokedex etc. Choosing your Pokemon and putting the effort in to make them part of your team is part of the appeal.
I remember playing Pokemon Red as a kid and buying the Magicarp and painstakingly training it to have it evolve into Gyarados around Vermilion City. And it felt like an accomplishment because it wasn't something I had to do, and most people playing the storymode didn't. SO I had this experience of playing the storymode with a Gyarads from an early point that was more unique.
Pokemon and how you build your team is just sort of different from lot of RPGs where you have way less choice for party members, so how comparable those experiences are... You can always grind fairly easily even pokemon with no usable moves, or catch higher leveled pokemon when you arrive to a new location.
Plus having your Pokemon be fighting machines is not the only reason to catch and train them.
Filling up your pokedex is one of the main goals given to you in the game.