They do, but one of its selling points is its case "fits in the trunk of a standard car." that suggests it's a pretty big drone and I default to imagining copte

They do, but one of its selling points is its case "fits in the trunk of a standard car." that suggests it's a pretty big drone and I default to imagining copters that fit in a hand, size in picture[2] more than I understand what 20kg means in drone size. No wonder it can fly a long way if it's massive. For energy density comparison, check the Wikipedia list of energy density of various things[1], starts with Antimatter highest, then nuclear fuels, Hydrogen[3] at the top of the chemical fuels with ~140 MegaJoules per Kilogram, then all the hydrocarbon fossil fuels hang around 45-55 MJ/Kg, body fat comes in around 38, coal around 30, wood around 18, glucose around 15, Lithium-air battery at 9, household waste at 8, and the highlight of our modern electronics lifestyle Lithium-ion battery at 0.3-0.9, barely ahead of flywheel at 0.3-0.5. [1] https://en.wikipedia.org/wiki/Energy_density#Tables_of_energy_content https://en.wikipedia.org/wiki/Energy_density#Tables_of_energ... [2] https://www.armytimes.com/resizer/-965_SXAhPeD1LTlB-xZuQwJvJE=/1200x0/filters:quality(100)/arc-anglerfish-arc2-prod-mco.s3.amazonaws.com/public/BEXU22MH7JEKTPZMAEC3IJH57I.jpg https://www.armytimes.com/resizer/-965_SXAhPeD1LTlB-xZuQwJvJ... [3] the catch with Hydrogen is a kilogram of it is 11 cubic meters, and a lot of that energy advantage has to go into compressing or cooling it to make it usefully dense, and maintaining the infrastructure to store and transport that safely.