I like and agree with the 20, 10, 5 countdown.  I can only surmise that competition trumps the vehicle. Given the fact the majority (99.9%) of people between the ages of 16 - 25 discover they can never be professional athletes, it must be human nature to seek another form of competition to satisfy the juices. Golf and boccee ball never cut it, yet people still want to be great NBA/NFL/NHL/FIFA athletes and eSports is the digital vehicle that lets people dream of being a pro.

If so, we may be discovering something interesting about the human psyche because I'd still rather be on a court/field/rink. 

A surprising addition to your info is the number of guys my age that I've discovered are into eSports. None of them admitted it but I've had 3 come clean about it in the last couple of months.

George