With the latest revelations from Larry Page's companies - Zee.aero and Kitty Hawk - in launching Cora in collaboration with New Zealand government, Airbus Vahana's first flight and the forthcoming Uber's 2nd Elevate summit in Los Angeles, the time is now ripe to get all aviation enthusiasts on the same page (& industry standard taxonomy).
My speech at the 22nd Annual B&GA conference last Fall, organized by Speednews is at https://i.imgur.com/HFhcit5.png for your kind review. This addresses technology readiness, major barriers, timelines and approximate market sizes.
More detailed analysis can be made available upon specific requests to query@AdvisoryAero.com.