Movement and travel is constantly an issue when constructing fantasy or science fiction worlds. People building such worlds love to create instantaneous travel options to allow characters to move about the world efficiently but regularly forget that this has real consequences for how the world should work. As an example standard DnD campaigns have teleport as a normal option and yet somehow countries still spend enormous fortunes to build castles and maintain armies. What good are armed goons or big walls when characters of modest levels can just teleport in, massacre anyone they want, and teleport out again? The problem is that the world creators have failed to adequately understand the consequences of completely changing the nature of travel and location.
A similar issue exists in science fiction universes. In particular I have read several books in the Old Man's War series by John Scalzi and the same sort of problems occur with FTL travel replacing magical teleport as the destabilizing factor. In that universe military organizations spread their fleets out over many different planets to defend them. Unfortunately even a cursory examination of the situation shows that any race could take all of their ships and just skip in to a system, annihilate the defenders just due to numbers, and raze the planet in a matter of minutes. They then could skip to another system, blow that up, and repeat. After a few days at most and perhaps even within hours they could have easily destroyed an enemy that had similar total military strength. Every war story in this universe should be over practically before it starts and yet even though this tactic works (because a few people try it a few times) nobody really makes good use of it because that wouldn't make the story much fun.
Part of this is the issue that combat systems in these worlds tend to be very much like fisticuffs. Ships and characters punch each other until somebody falls down and those with a numerical advantage win the fights. In real combat this isn't the case because people and vehicles are so incredibly flimsy. Bombers and fighters don't punch each other till somebody falls down - if the sky is full of enemy planes it becomes incredibly easy to blow them up. The real world has an awful lot of instant death and very little of "Captain, the shields are down to 25%!" In the real world the tactic of 'put all my stuff in a pile and drive it around to enemy bases' is suicide while in fantasy or scifi worlds it is usually unstoppable.
Of course most people don't care about this stuff. They like fisticuffs in space and don't really care that the universe and the way warfare is conducted makes no sense. They also like teleporting about and aren't so worried about the fact that castle and army based warfare is a hilarious joke in such a world. I get that; internal consistency isn't what makes fantasy worlds fun. It bothers me though. I want to create a world that makes sense and reacts to what the characters do and I can't do that very well when important people are committed to monumentally stupid strategies.