Also, why can you socialize with the neighbors. Parents used to be super comfortable with "tommy is coming over for dinner or spending that night"

Is that still the case? I don't have any anecdotes on this.

There are less kids overall.

Kids today have more activities, so you won't meet them just by randomly going outside.

They do a lot more activities at home on computer, again you won't meet them randomly outside.

Parents are not even allowed to let their 6-7 years old outside alone, meaning they would had to be with them. Meaning kids won't get habit to he outside nor will find friends outside, even if some kids are around.

And if those other teenagers have phones, they expect you to organize it all by phone. They have own friends they socialize with and coordinate via phones. It is rude to just show up without calling first and you need phone to be reachable by other in the first place.

And other kids will not call on parents home. They are shy or scared.

When kids went to Timmy, pwople assumed landlines. Before landlines, it was accepted to just show up. Today, expectation is phone.