In many JPRGs, the characters have a predetermined pattern of growth, thus automatic leveling makes sense. The Persona series (3 and onwards at least) is odd in the sense that leveling is automatic, but players will occasionally have to decide which skills to forget, since skill slots are limited. Usually the choices are simple, new skills are often straight upgrades to a previous skill. However, there are a few characters who have diverse skills that can fill different roles, but not enough slots to fit them all.

Pokemon is also like this, except that it's very common for Pokemon to learn a diverse enough pool of skills that the decision about which ones to keep can be hard, and that's even before you factor in things like TMs that allow learning new moves.

(There are a few Pokemon with very limited move pools, like Ditto, Abra, Magikarp, and Unown; those Pokemon are generally useless (though Abra and Magikarp evolve into better Pokemon, and Abra's Teleport can at least be useful outside of battle.)