You may not have used them but there were definitely third spaces for children and teens in the form of play areas and parks. Add skate parks to that list if you grew up in the early 00s, and probably something else before that.
Maybe. But we got on our bikes and went there. We'd sonetime bike 20 miles in a day...for kicks. Just to bike.
There's a third place in every kid's head - and every adult's head - if we don't exercise that muscle (so to speak) we will lose it.
The evidence seems to say we are losing it. The adults, and in turn the kids.
Fwiw, I liken the situation to Legos. When I was a kid you bought "raw" legos and then created whatever TF we could imagine.
No. Wrong. Answers.
Today, Legos are highly kit-focused. That is, build THIS. There is a right and wrong answer. Ffs Legos today intentionally mitigate the opportunity for kids to color outside the lines. Just the though of that straight-jacket is demoralizing.
p.s. Yes we occasionally went to a skateboard park. But we also built our own ramp for when we couldn't. We also found a drainage ditch in the woods off Rt 195 that we frequented in the summer. 100% adult-free.
The "Dogtown and Z-Boys" story could never happen today. Not to belittle depression but that's depressing.
Lego still sells buckets of bricks. When we take our kid to the store, he wants the kits in pop culture themes. When he's home playing, he wants more basic blocks. Classic example of industry selling to our wants, not our needs. But good news, it's lego: the kits rarely stay assembled longer than a few days.
Children being indoctrinated into brand-culture is another horror show to discuss some other time.
But to your point, not only don't they get to color outside the lines, they're assimilating into the Culture of Consumption and the Culture of You-Are-The-Brands-You-Buy.
I think you missed my point about lego. My kid builds the whatever-theme set, gets some satisfaction for completing the task, and then within a few days has used the pieces to make something of entirely new. He "consumes" the brand-culture product a few times a year when he gets kits as gifts or saves up to buy them, and for the rest of the year, uses the pieces to color outside of the lines. This flexibility is pretty much unique to lego.
I've been curious watching the market after the lego patent expired. That market is dominated by rather intricate models [e.g., 1]. They aren't attached to big brands, because of the "nobody got fired for partnering with lego" effect, but the quality producers aren't doing buckets of bricks either. (On the other hand; as I write this, that Taj Mahal set is over 3k pieces for $76. The color is boring but holy heck that's a lot of (itty-bitty) parts!)
Unused land is fenced off and teens are chased away when they congregate now.
Actually, nevermind teens, even adults can't find third spaces now. There's vanishingly few places you can comfortably exist without being expected to pay something. The library might be the final remaining space like that, and my local one is sadly closing down.