My next-door neighbor (mom to an 8yo and a 6yo) feels that same way about childcare.
Like I said, I wouldn't pay for a gym for myself when playing outside is free, but presumably there are some people who do it. My kid dislikes playing outside, and I don't blame her. After about 5 minutes, she's covered in mosquito bites. It's hot and humid most of the year, and sopping wet the rest. There's no playground in our neighborhood (closest one is ~15 minutes away by car). The only kids her age are the unsupervised neighbor kids, who think "playing" involves riding bikes over other people's stuff, and the little girl at the far end of the street, who isn't allowed out of her own house (they live on a dangerous-due-to-traffic corner - I don't know why she's not allowed to play in other people's yards, but she's not). And when she does play outside, she's certainly not getting any exercise. She moves more jumping on the bed than she does chalking on the driveway.