I assume the simpler explanation to be that many billionaire/dictator's dream hobbies turn out to be starting or funding outlandish, impossible, vanity projects

I assume the simpler explanation to be that many billionaire/dictator's dream hobbies turn out to be starting or funding outlandish, impossible, vanity projects while completely insulated from consequence and isolated from reality. Yeah, scuba is cool, but I've got a handful of pet engineering projects I'd love to tinker on if I won the lottery (while farming off any drudge work that comes up). I assume all the businesspeople and politicians I also observe to fall into this trap just do the same with their particular area of expertise.