What'd help way more with waste is if they would stop making like 75% of the part count of modern sets short 1x1s and other really tiny—often flat-topped, because the box photo mustn't display any nubs, I guess—pieces. If my kids take some legos outside, those are what get lost permanently. I get them to pick up what I can, and make a pass myself for any they missed, because as toys go they're gold, but some of those tiny pieces are for-sure buried in my yard.
That'd also make the sets more playable—repairing play-induced damage on a modern set is hell because of the fiddly little constructions they use, and there are few exposed nubs to connect things to for expanding/customizing/having-minifigs-stand-on-it, without tearing off a bunch of pieces.