Lego last long and are repurposable. I personally think they are not really meant to be built according to instructions in the long term. It's the same way a framework is not meant to do a todo app.
It's something the kid does on first pass when learning how the system works, before starting on the actual cool stuff.
There's kind of two types of sets made today the play sets for kids and display sets for adult collectors. I do agree though that LEGO isn't really plastic waste because most of it doesn't get thrown out and kids collections get reused and resold to collectors and are relatively rarely thrown out.
