The most appealing thing for me regarding generic fantasy… the default assumed world of fantasy… is the suspension of disbelief and just freeform structure of the geography.
A GM can put as much or as little thought into it as he wants. A detail oriented GM could consider the mountains between two countries and how it limits trade yet makes one route particularly valuable. Also those tall mountains impact the weather in the following ways…. etc. And can have a satisfying world building experience.
On the other hand a GM who wants to say that the party’s travels have led them to blah blah blah and there is a queen who needs help with an evil wizard… bam! Done! Just as satisfying.
The biggest concern here for me becomes movement. The ability to fly halfway across the continent or teleport or whatever means that the GM has to work up some info on the interveneing spaces or think about how things interact.
That’s not to say all movement is horribly. If I place a magic portal somewhere, I get to decide where it goes. It could be a kingdom on the other side of the world, a different plant, or another plane of existence.
What I’m saying is I want my world built in bite sized chunks… possibly using random tables to make it event faster.