Founders can be chasing a dream and in doing so mesmerize investors. Or they capitalize on that same dream being the investor's. Even if it's not viable, it can still be really fun company to work for and/or earn money at. Even if there is a small lane for that sort of flying machine, the sheer number of companies purportedly working on something like that is suspect. Given the huge costs for development and certification, and the small number of vehicles that will really get deployed (certainly for the first so many years), there must be many that are never going to make their money back. I worked for a drone-adjacent company and now my LinkedIn is swamped with these startups.