This varies majorly by child, parent/caretaker, and environment. For instance with my children if we go outside, then they are on full auto mode. They could play in the yard by themselves pretty much all day long as long as at least one parent's nearby watching them. But if we're indoors then they demand full attention. On the other hand somehow our nanny has got them to be able to happily play indoors while she mostly just chills out doing stuff on her phone or whatever - and I have no complaints since it works out great for everybody.