I'm very much an old school Pokemon fan, only played the first 3 generations of games so I haven't kept up with the meta. From my understanding, rare candies were quick and easy ways to level up a pokemon but had a major drawback, EVs do not increase and cannot be recovered if you're max level.
In my playthough, I have amassed hundreds of experience candies and rare candies and am contemplating using them or selling them. EVs could be increased with the grit rocks and leveling up pokemon to the 60s and 70s seem easy to me so I don't really know if I even need to use the candies except for my highest level pokemon.
Are there any drawbacks to using these candies to gain experience and level up my pokemon?
I don't want to skip out on increasing stats if I don't have to.