step by step development of logistic system based on autonomous electric vtol aircraft

when batteries become more efficient in weight and volume than fuel, 

cargo aircraft and passenger aircraft are slowly replaced with electric cargo aircraft and electric passenger aircraft, when lifespan of aircraft is over 

when cargo aircraft become electric, they become cheaper to fly, 

so market will require more electric cargo aircraft 

likely maintenance of electric aircraft will become cheaper too 

more electric cargo aircraft will lead to a shortage of pilots, nowadays there are atleast 2 pilots per aircraft, 

this will lead to a market demand to make electric cargo aircraft fully autonomous and electric passenger aircraft 1 pilot with fully autonomous capable ai co-pilot 

availability of cheap, reliable autonomous electric cargo aircraft will lead to that factories, warehouses and raw material sites will demand vtol capability so that vtol autonomous electric aircraft that land vertically on site to be loaded with cargo and fly to destination and land vertically for cargo to be unloaded on destination site