Similar concepts (i.e. connect to random strangers' devices when in close physical proximity, and trade mini profiles/trading tokens/whatever) have been done at least half a dozen times, both before and after Nintendo, but somehow they never seem to stick. Street Pass may have been the most successful iteration that I'm aware of. I think that it's hard to get critical mass. Users are excited at first when they set things up, but after a few days or weeks of not getting any hits, they tend to lose interest and turn the service off to save battery life.

It was never implemented in PoGo, was it? Because that's where it very clearly should have gotten a spiritual successor.

Not that I'm playing that anymore, with its predatory scheme. Orna all the way, now.