I wish they continued selling single-use bags and instead required them to be biodegradable/compostable. It's fine to charge for them, too.
Why? Because sometimes shit happens and you go to the grocery store without a reusable bag. You don't want to buy a reusable bag, you already have them at home. And those reusable bags are rarely recyclable or compostable either, so are they really greener than compostable single-use bags?
As I understand it, plastic checkout bags are banned federally, regardless of which sort of plastic they are made of. It sounds ridiculous, but that's what the law appears to say.
I'll be perfectly honest: I don't care about the technicalities. Anybody can still buy compostable garbage bags that, to a layperson, sure feel similar to any other plastic bag.
If it is biodegradable / compostable, it should be available for purchase at checkout points for a small fee, regardless of whether it is made of plastic, advanced biopolymers or unicorn semen.
The only place I see with degradable bags at checkout is Whole Foods with their (rather robust) paper bags. All other shops have done away with disposable bags and it's an annoyance to customers when they forget their reusable bags at home.