> ... it takes incredible levels of incompetence to be lost in sinay for 40 years.

That 40 years wandering in the wilderness was "lost" only in a poetic or opportunity cost sense. More literally, it was divinely-assigned Punishment Detail:

https://en.wikipedia.org/wiki/The_Twelve_Spies

Also note that the story is in Numbers and Deuteronomy, not in Exodus.