Something that needs to be said about Blue Mages in their respective games: They aren't there to be 'flashy' by just copying moves. They exist to fill niches that other jobs/classes simply cannot.
In FF5, you have the Level X Magic line, which on the surface isn't that great due to requireing a lot of trial and error, but its uses in conjunction with other spells like Dark Spark (Halving level) on the right mobs can provide out of the box ways to eliminate foes, almost like finding a secret path or shortcut in another game.

In 11 the list is *bloated* as hell and most of the spells fall off of usage save for a few of them.
>Feather Tickle/Reaving Wind reducing the resource on enemies that enables them to use special moves, very useful for when you want something to NOT use ANY move at all
>Osmosis stealing a buff from an enemy that other lines of magic of a similar effect cannot
>Subduction being an AoE damage spell that severely reduces the movement of an entire group of enemies
>Mighty Guard providing its unique version of Hatse/Protect/Shell/Regen on top of stacking with the former
>Cruel Joke inflicting Doom on enemies that wouldn't otherwise been able though this has been nerfed because SE is no fun
>Jettatura/Absolute Terror stunning certain enemies that otherwise cannot be stunned by normal means

And that's just the tip of it. Point is, Blue Magic isn't just for the cosmetic of using monster abilities, but for doing something other classes literally cannot do because they come from monsters.