I have a nephew who's travelled the world on parkour now. Been to North Korea, Japan, Cali, countless other places doing 'demos' and stuff. He's yet to be to badly banged up and he's currently in university. It's given him lots of opportunity and pushed him to an amazing level of physicalness. So there are upsides. It is a sport now and while the internet glorifys street stunts gone proper or bad. The real work and training happens behind the glamour of the gif.