the only way to make the typical final fantasy / pokemon rpg combat fun is to either introduce some gimmick into it or to remove it entirely
Gimmick example: mother 3 uses an interesting gimmick where pressing the A button in tune with the music beat allows you to chain attack, which is a good addition because it completely removes the whole 'just keep pressing A to win' mechanic. you can still basically win by pressing A but using the rhythm mechanic is actually pretty fun and it gives you an advantage, especially in boss battles.
Removal example: the 1-dimensional rpg combat where you simply target an enemy and choose to attack them isn't fun in any way. Some games remove this rpg battle system entirely and opt for more meaningful mechanics. A good example would be fire emblem, which is basically an rpg game slapped on top of a turn based 2d combat system. It works well but the depth of the gameplay is sort of removed to make room for the rpg mechanics like leveling up and character development. The tactics genre (Final Fantasy Tactics, Tactics Ogre) is another example of 2d turn based combat. They have almost no depth besides deciding where to move and how that will affect the battle. Games like Advance Wars handle depth better than those
tldr; rpg combat isn't fun. you can either improve it slightly which will possibly make it fun for like 5-10 times before it gets boring, or you can remove it entirely and opt for a different combat mechanic, like 2d turn based strategy, or real time bullet hell stuff, or whatever
