Is it better for kids to play with toys or be more interested in music and arts?

My 19 month old could careless for toys, so we stopped buying them. But we buy him play musical instruments and he has art supplies or his new favorite thing is an empty milk gallon and a straw and he goes around playing with it and singing. He likes cars but actual ones and the play ones he pays attention to them for about a minute then moves on. He does have a little cleaning set, it has a broom, mop and a picker upper. He plays with that when he sees me cleaning. He has a ball, and a little tikes car, so that's what he actually likes . Well the other day my in laws came over and saw he doesn't have any toys, like their other grandchild(literally has every toy in the book) and they said I'm ruining his infancy by not getting toys for him. I've been thinking about this a lot ever since.