On the subject of worldbuilding issues though: Has it ever been established who exactly governs the Pokemon world/individual regions?
Tricky question as honestly the day-to-day government that actually run a region is never really seen as they kind of oddly don't matter as far as the games are concerned. One important Gym Leader here to mention is Drayden who is specifically said to be the mayor of Opelucid City. This is notable because this has to be specifically said, as if it's something only pertaining to Drayden and no other Gym Leader.
It would seem to be the case, and the Pokemon Special Manga somewhat agrees, that it's the Pokemon League (or whoever runs the Pokemon League, which in the Special Manga is the "Pokemon Association") is the organization that's in charge or Pokemon-related legislature. But, as seen with Chairman Rose, who is the president of a major company and seemingly not with any political or government group, even if there's a government group backing the Pokemon League they may be able to govern anything related to the Pokemon League (Gym Leaders, Pokemon Centers, PokeMarts, the League Tournament) they may not have legal power and to do anything outside their juristition have to get permission from the region's government (and depending what it is they want to do may require going to a different level of government). Going back to Drayden, being the mayor of Opelucid he's probably able to assist the Unova Pokemon League if they want to do something within Opelucid City or the surrounding area, but that's a rare case and it also creates a rough position for Drayden as he needs to decide whether what the Pokemon League wants to do would be beneficial for Opelucid City or at least willing to compensate if there is none (and what and how much that compensation is).
Alola is another interesting case as the Kahuna are specifically said to be in charge of their island. And it's kind of hard to argue against that when the reason this is is because a Legendary Pokemon said so all whom have no problem unleashing their wrath upon those who displease them (of course the Island Guardians would very much be invested in picking the best person for the job). And as we've seen the Kahuna's aren't alone as there's plenty of people and groups helping keep the day-to-day things running.
However, outside that, we haven't really seen any government figures*. Most Gym Leaders are at most community leaders who have some clout but that's it and really only within the town/city they are the Gym Leader. Elite Four seem to be more direct agents of the Pokemon League, while they may not have any sort of influence in any town/city if a matter is considered to be under the oversight of the Pokemon League or a Gym Leader requests assistance from the Pokemon League than an Elite Four member can step in and take charge of the situation until it's cleared up. As for the Champion, oddly the Champion just seems to be a title hold by the trainer who beat the League Tournament the Pokemon League runs. The Champion has no responsibility to the Pokemon League aside defending their title, however the Pokemon League would definitely hire the Champion as another agent of theirs if the Champion chooses to be (such as with Lance and possibly Leon). The Pokemon League also probably sees the Champion as a "last resort", a trainer they can approach and request help from (if they don't work for them) if they need more "muscle". That is probably why we see Steven, Wallace, Cynthia, & Alder getting more involved with Pokemon League issues though Iris & Diantha seemingly don't have that much involvement.
* Okay, yes, we have seen Interpol via Looker, Nanu & Anabel but that's another level which involves multiple governments.