I think this is something the kids should decide. I wouldn't like it if someone told me I had to pick a sport and 2 other activities (or worse yet, someone picked which sport, and which activities). I think during the summer, it's reasonable to expect a kid to get involved in something other than just staring at their device or TV, but during the school year, school and homework is enough to occupy their time if that's all they want to do.
I would not allow my kids to have an activity (or several activities) every day because of the sanity of the family as a whole. I can't take just one kid somewhere, usually I have to drag them both. And I don't necessarily want to spend several hours each day driving from place to place (and shouldn't have to). There is sometimes something going on for Scouts on the weekends but I try to keep weekends open so everyone has some downtime. I cringe at families who are out at games every single weekend and can't make plans with anyone or go anywhere for a weekend getaway because everyone expects the sport to be the top priority--that's just not how I want to live my life.
