I think there is a chance to reduce but there's an upper limit, theres a reason we moved towards this packaging, cost, scale and convenience

The Logistics of having to bring your own containers is a pain in the arse and impractical for those who don't have their own vehicle, imagine people on the bus hauling jars up and down to shop, and the integrity of those containers will also deteriorate with time

I have experience in glass recycling, and the best way to deal with glass is to smash it, or you carrying around air, cleaning plants are only able to process so much, so smashing works better, it can just be broken down and re-used that way

If i don't clean my containers I buy a product, and I get sick, I can blame the store and that causes its own set of problems

Do I think landfill/disposal could be better sure, food stuffs could easily be pushed towards setting up biogas and composting, enriching the material and creating something that can be resold to the market

Plastics are really the tough one, theres so many different types, and none of these solutions like making bricks and stuff is actually worth it, its just a marketing gimmick IMO