Brief.
Final Fantasy II does have the very important role of being what not to do in a turn based RPG, which helped Square in their later projects. Despite the overall plot being more interesting than the surrounding titles on the surface, the entire experience is hampered by the game's progression being, to put it simply, broken.

Instead of an across-the-board level system for characters, you instead prioritize levelling their weapon proficiency, and can evolve individual stats by participating in combat and taking certain actions such as dealing or receiving damage. This matters significantly less as the game goes on, but this makes trying to jumpstart the levelling of characters incredibly tedious. While I imagine this was intended to coerce the player into strategizing their battles to min-max character growth, it doesn't necessarily succeed at that in ways that at any point feel good.

This system may sound familiar to Elder Scrolls players in games such as Morrowind, which I feel incorporates this idea much more smoothly due to it being action oriented. FFII is a turn based game, with very few options to directly influence your growth, and many other factors that make the game nothing more than a chore.