Playing outside is part of it but like I replied earlier:
I feel we had way more in terms of internal resources like imagination, inquisitiveness and creativity plus we had to go out and find things instead of tapping screens and having data come to us. Totally different ways of triggering endorphins and the joy of discovery as well as how much more physically active we were.
Thing is it was always different, very rarely (never even) would two days be the same because you'd always cook up something fresh and new whereas these days the basic frame of "Rise, eat, iPad [INSERT CONTENT], sleep" is very different. I feel we gained so much more tangible real world experience in that you learned a heck of a lot by pushing all kinds of limits by doing wise/dumb/reckless/inspired/dangerous things just because you were a group of kids exploring your collective impulse and drive to test the limits/be different whereas now the pressure is to conform and be the same as everyone else.
In terms of development there is an immense difference in endorphins/neural connections created doing real world things vs watching someone else do it via a screen. Thats the main gist of the thread. Its like how we played video games but now kids gladly watch someone else playing.
There is also a frailness that is socially sanctioned and enforced from a very young age that is inherently demasculinizing and its being fought on all fronts. From the dumb father stereotype via Homer onwards to the "Strong independent woman" who will turn you into a son-husband hybrid for emotional support as well as the fact that most teachers are women these days so rough and tumble time doesn't happen as its not tolerated and taught as wrong from the jump. No more handing out lumps or testing your chin as aggression is being trained out and along with it inquisitiveness, creativity and the resourcefulness that comes from the learning experience.
Its actually a huge topic. Way beyond the scope of the OP but that was just a hint about the depth of what is going on around us. No going back as the Game only loops in one direction but its very interesting.
You can see the effects of the creativity drain very easily since the net kicked in. Compare movies, games etc.. from the 80s/90s with 10s/20s and you'll see what I mean about doing more with less as well as the homogenizing churn that has been inflicted on the world since it became a global village in which the peons daily annihilate their Limbic System in exchange for another hit.
In a nutshell this excess we are seeing on the outside is the equal and opposite of the hollowness within, modern generations especially. The implications of this lack of internal resources will be most acutely felt within a couple of generations when
their grandkids have got next and will know not how to do anything the screen doesn't tell. You won't be here but its easy to imagine where we're headed as a collective because people choose to sit back and do nothing bar amuse themselves to death.
To sum it up the main difference is:
We lived life, direct and in the flesh whereas modern kids are content with watching someone else live it. That is indicative of a far deeper disconnect that nobody seems to mention or have noticed because of the addictive nature of this tech that nobody wants to admit has got them open. Kids are getting it the worst as they know nothing different. Its the only life they know which is
akin to walking with a limp because someone gave you a stick since birth even though your legs are perfect but because of this you miss out on the thrill of running and jumping because you rely on externals that limit the internals you're gifted with.
There's levels to this and its subtle yet obvious for those who can see the bigger pic.