Firstly I now have to buy garbage bags, where I previously reused shopping bags. That completely negates the benefit. But let’s ignore that and say most people just trash them.
Even in that case you’d have to reuse a reusable bag 20 times to break even. I don’t know about you, but on average maybe I get 0-5 reuses out of these bags. That’s just squarely worse off than we were before.
I’ve had the same reusable bags for probably 5 years now and not a single one has failed.
As in all things, moderation, do the 80% etc...
Hey if you've been using the same bag for a shopping trip every day, for all that time and never replaced it or got another, and it wasn't organic, you're almost halfway to having a smaller environmental impact than just using single use plastic bags all that time.
https://www.cnn.com/2022/12/13/world/cotton-tote-vs-plastic-...
So you'd need to reuse a cotton bage 70-1000 times most likely to come out ahead. Or you could reuse cotton you already have and lower that number to effectively 0.
I'm waiting for someone to invent the re-usable dog-poop bag. ;)
Sure if you got random cardboard one it won't be that great
Shopping bags were always terrible garbage bags able to hold only tiny amounts of trash meaning you had to use a ton of them and as many as you needed the average household received 100x as many bags as they could profitably use as trash bags. Consider throwing everything wet into centrally located large trash receptacles with large bags and either not lining small trash cans or lining them with paper bags.
TLDR buy better bags and use small paper bags.