As an (increasingly) old, I don't participate in all the fun stuff that's around but I'm happy for the kids to enjoy their time on the lawns. Philly's slowly gotten better at providing the occasional nice space for people to congregate outside and enjoy an adult beverage or two, with more bars and restaurants figuring out how to provide such spaces given the relatively small lot sizes most of them have, and with semi-public endeavors in various spots.
That the weather has remained almost cool most of the time has helped.