Most of that feels like a very extreme sports lens on the topic though. My experience of rollerblading was as mostly a 30 something where a bunch of us would do evening skates on the bike path or on paved paths in the city and park, etc. At the end of the day, something he says at the end of the video is probably right. It was a fad and once enough people grew out of it or just stopped doing it as much, the network effect of it being an activity to do with friends decreased.
https://www.youtube.com/watch?v=xVB6ef9JWSk