Certainly. I found that Dune had excellent world building in regards to its 'magical' component. The Bene Gesserit Witches, while possessing incredible powers, are also essentially conditioned to be completely subservient and possess little to no ego unto themselves, preventing any individual member from a desire to exert direct control (yet even this isn't wholly true; as the group has their own ambitions and desires that they carefully keep hidden THROUGH this subservience, and because their abilities are too subtle to be effective in direct confrontation).

Vampire; The Masquerade (though a game) has good world building in regards to its secret vampire society, with the explanation as to the masquerade having little to do with humans and more to do with the fact that they're all too busy killing eachother to want to deal with *another* foe. Despite this, plenty of vampires DO inhabit high society and government positions, and keep themselves hidden more out of fear of other vampires than what humans would do.

Avatar, The Last Airbender (though a show) had great world-building where you can see the direct results of the magical system on the society within it. The Earth Kingdom's landscape/cities all function AROUND the ability to Earthbend and it has the most intricate transit system of all nations due to this reason. The Fire Nation has the most advanced technology of anyone, far surpassing all others, because they have a unique, portable, accessible heat source constantly at their disposal. Etc.

One that took me out of it? Harry Potter, just at the top of my head. A master wizard has enough power to wipe out dozens of battalions with a flick of a wand or assassinate select individuals with ease and you're telling me they all borderline-unanimously decided to keep to themselves out of every human conflict ever? Come on now.

I didn't mean to suggest that magic should cancel out medieval society, because even in fantasy worlds built from the ground up they go through a medieval period, all I meant was that said society would grow and develop *alongside* these magics and having them and their effects integrated into their society, rather than nothing being particularly different. If your world includes a group of superpowered humans who HAVEN'T followed the trend of literally every other powerful group to ever exist... why is that? There ARE reasons why people who have vast power wouldn't want to *exert* that power, but it has to be more believable than "We just didn't want to", and IF that's the explanation, then what is the CULTURAL reason that enforces that? Is it some kind of religious orientation that commands pacifism? If you try to deviate, do you lost your abilities? Etc.

Same with regular fantasy. If, within your fantasy world, there exists a group of people who are able to approach a noble and command them to give up all of their gold and this noble is magically bounded to obey, there HAS to be some legal recourse from that or military protection preventing it. There's no way a world would exist where such powers were learnable that a society would just let slip under the rug.