Bags in my area have always been at least double-use, first you bring groceries from store, and then you use the bag for collecting trash to take it outside. In

Bags in my area have always been at least double-use, first you bring groceries from store, and then you use the bag for collecting trash to take it outside. In places where plastic bags are banned, what do they use to collect the trash? Plastic trash bags? I also read that you need to use a cotton bag between 7000 and 20000 times before it becomes even environmentally neutral depending on production technology. So is it really useful to ban plastic bags, maybe an improvement in technology is needed, some new polymer formula which decomposes faster but still cheap to produce?