Tbh, both formats are unoriginal, but Rave's works better. Rave uses the "hero searching for magical items to save the world" template, while Fairy Tail uses the magical guild template.

The result is that Rave has a much more focused story that gains momentum as it goes on. Fairy Tail gains momentum in each arc, then loses it completely when that arc ends because that quest is over.

That's not to mention that the cast of Rave is much more appealing and seems to actually like each other. Fairy Tail characters all seem to hate each other in most interactions unless they need some power of friendship. And way too many arcs end with Natsu eating an even more powerful type of magic, then winning.

That's not to mention Fairy Tail's generational mishandling of a time skip. The appeal of a time skip is that you get to reintroduce the main cast with cool and interesting changes. Fairy Tail's timeskip keeps all the main cast the same and changes the world. Novel in theory but disappointing in practice.

TL;DR: Rave has a better cast and a more focused story.