Exactly. Joby is just one of many. They might fail and probably will.
The reality: multiple companies are currently flying viable prototypes. A lot of the issues are at this point no longer issues: they are solved problems (or at least very solvable). The solutions might not be perfect but we are beyond proofs of concept at this point: these things are flying.
The math is known, brutal, but not a show stopper. In short, within acceptable parameters of e.g. limited range (but also cost), these things can function as advertised. There are a bunch of uncertainties remaining that are essentially non technical and boil down to regulation, market dynamics, and people buying into this stuff.
The main psychological issue is that people have been trained to believe that planes are complex machines that require advanced skills to fly, a lot of maintenance, and a high cost per hour/mile. While they are reluctant to let go of these notions, none of that is true for electrical planes. Think of them as a vacuum cleaners with wings and some power source (i.e. batteries or fuel cells). Simple to manufacture, maintain. and operate. Reliable too because there's very little that can break.
It's the exact opposite of the complex, unreliable, expensive to build and operate planes that we have today. Their unreliability requires constant vigilance in the form of maintenance, inspections, and vigilance that requires extensive practice and training. You are not even allowed to operate a plane unless you can prove that you have gone through extensive training and have enough recent experience flying a plane. Flying a plane requires deep knowledge of all the complex machinery, its failure modes, and mitigations.
Electrical planes not so much. The prototypes on the market right now have in common that they are "fly by wire" where pilot inputs are very limited and dumbed down to the point where you might wonder what the role of the pilot exactly is (some of these things are autonomous from day one). They are mechanically simple (lots of reliable electrical motors, wires, and batteries). And they cost a certain amount of $ per hours which is a function of the (long) mechanical life of the engines and the rest of the plane and the cost of KWH.
The main argument in this video is that the FAA is going to be a PITA. That's correct; that's their job and they are good at it. But that doesn't mean it's a constant in the universe. Ultimately some country will start allowing these things and likely at that point FOMO and politics kick in. Simply put, if e.g. China (a likely place for this to happen) starts living in the future by manufacturing and operating these things at scale, there's absolutely zero chance of the FAA being allowed to hold that back in the USA for very long.