JOBY FAA Certification timelines is 2024
See, What Elon has said about same 2 years back !!
You don't need 400 Wh/kg - That's for 300-400 miles aviation aircraft - Evtol market is 100-150 miles for ride sharing !!
The real problem is manufacturing hell - The capital it needs to bring product to market. Any tom dick harry can build a prototype - The manufacturing is the critical puzzle - Toyota has skin in the game with Joby Partnership & Stockholding.
James Kuffner is guiding the Joby with 1 B $ stake in Joby through toyota