I really dislike Elon as a person, but didn't the hyperloop POC work? I admittedly haven't followed it in long time.

Definitely not. The companies that were prototyping it all went bankrupt. The "Vegas Loop" is just a tunnel with Tesla car traffic in it and I don't even think they're fully self driving! Very very underwhelming. Not even remotely close to the "NY to DC in 29 minutes" which he promised.

We would have been much better off with investment in tried-and-true boring old trains.