I think this is a FASCINATING subject, and I have a friend that I talk to about this all the time.
To be clear, I don't think yabu, but I also REALLY see the case from the other side.
And I do think there is a 'thing' now that we don't/feel we can't allow our kids out to play like 70s kids and earlier were allowed to go out and play - we do monitor our kids more closely now.
There is, I think, a massive argument for allowing kids to set their own agenda, make their own play and feel what it's like and handle what it is to be bored.
There are also masses and masses of opportunities. Certainly more than I was ever given. And like a previous poster, my DD wants to experience every single one of them and more. So for me, what my DD does is child-led. And I DO fret about her being too busy and too tired, and we do a LOT of TV in spare time, because I WANT her to chill too.
And if we can afford it, we want to give her that/those experiences and learning things. My dd has regularly done 8+ activities every week (some school provided and the rest we opt into) since she was 3 and she's now 13.
The quandary I have is: Do I make her stick at things which become harder/she loses at (in a sporting context)/she has to practice to improve, or do I just (butterfly like) let her move on to the next new shiny thing.
I'm not criticizing or defending, but I would suggest a lot of what 'busy' families who can afford it do is probably child-led.