On topic, in your opinion, what degree of detail do you think is best for playability in world building. If 0 is no world building at all beyond the needs of where the PCs are right now, 1 is a rough sketch map with maybe some names on it, 5 is a short primers with a paragraph each on nations, religions, factions, etc... 7 is a full primer on each of those things, and 10 is a Kingdoms of Kalamar level of meticulous detail, what numerical value would you give it?
And just to remind everyone, we are talking about world building an RPG setting, but not necessarily YOU doing the work. The scale I just provided applies to something you might make, but might also purchase or adapt from a media property or develop with a community or whatever.