Hard to not to have a cognitive dissonance on this one. As a kid I loved Lego, and my kids have plenty too. But thinking of all that plastic that eventually makes its way to a dumpster... Lego is brining so much joy, but you can't ignore the environmental impact too. I am actually disappointed at myself about not having thought to buy second-hand instead.
It is an interesting example of why the pollution problem is hard. Here we are not even talking about anything essential for the quality life, not even comfort. That's basically "just a toy". But, theoretically, would we be willing to give it up if we don't find an environmentally friendly way to make it?