I did quite a lot of activities as a child (swimming, dancing, horse riding, art lessons, netball, soccer, acrobatics, etc... obviously not all at once) but I don't know ANY kids who played as much as I did either. I was always outside, playing with toys or imaginery friends
My kids also do extra activities, but it is only one hour a week each, so they still have plenty of time to play! We do nothing on the weekend either. They HAD to do swimming until they could swim, and then one other activity each.
I thought it was very important for my kids, especially DD1, to do something outside of school, as she struggles a lot acedemically and I wanted her to be doing something else to give her confidence.