This paper "Electric VTOL Configurations Comparison" [ https://www.mdpi.com/2226-4310/6/3/26/pdf ] presents a pretty decent energetic analysis of a few of these eVTOL projects (including Lilium) and is very generous to them.

Lilium is vaporware. Ask anyone who has worked in the space. Or just look at it. Or their promotional materials.

Ducted fans huh... meh. I don't think they have an interest in people understand how fly-y/hover-y things actually work.

I do applaud the investors for their vigorous desire to increase the velocity of money throughout society, it is important econometrically. Somehow I doubt they'll be happy to see their currency shredded by 36 rc brushless motors struggling to thrust an anemic wing into the sky though (before its glorious ~250km/h cruise to destination [of course])--and then ~15s landing hover.

What exciting times to fly in.