It’s not, I’ve been building custom orthos and finding freeware airports as I go. For the former I’ve used a zoom level of 16 (may have to dial that back soon) with the great Ortho4XP tool.
For the latter it’s amazing how many pretty high quality airports once been able to find with some carefully targeted searches- there are a handful of folks who have been building lots of airports across the African continent- I may have gone slightly nuts downloading all the sub-Saharan ones…