>>510483322 (OP)The location is obviously ripe for tourism. Saudi are wise to try and recreate Sharm's tourism successes on the other side of the Straits of Tiran.
When Egypt get their high speed rail online, and if the bridge/tunnel between Sinai and Saudi gets built, NEOM will be in a prime midpoint connecting Egypt and Saudi, and might attract a LOT of Egyptians to move there, relieving a lot of pressure on Cairo (and Gaza?).
If Saudi have to build a new city, why not build it in a straight line? It allows you to simplify and centralise all resources.
This is massively important in the desert were resources are strained. A line is the simplest shape.
Humans have generally built civilizations on rivers, so why not try and emulate this by creating a man made river?