If you're doing the storyline, I can see why you think the Limit break system is boring. Once you start getting into harder instances, such as Amdapor Keep or the hard mode primals, you will see that planning when to use them and which role will be using it will have a huge impact on the outcome of the fights. Using meteor on Ifrit's nails, using single target LB to finish bosses and so on.

I can see this being frustrating in the beginning when you don't see Limit Breaks as a key element of some instances and you want to try them for yourself, but you will get to like the system. I'm mostly playing BLM, and if we need BLM's Limit break and there is a BLM with better gear out there, I will definitely let him use the LB because it will be more powerful and will benefit the entire team more. You need to think of the system as a party mechanic, not as a super flashy action done by yourself.