the single use plastic bag ban here has worked fine as far as I can see. The reusable thick ones cost very little, and my trader joe insulated bag full of them that I use every time has worked fine for a year, although it is like carrying a purse to the grocery store every time.
I used to notice all kinds of thin plastic bags that went aloft and ended up in the middle of nowhere on sagebrush, flapping in the wind, but those bags no longer show up much, and the old ones get eaten up by UV radiation. The first time you see a dead jackrabbit with its head in a Walmart bag, it changes one's vote. getting rid of the single use bags is a winner, in my opinion, and I never go to sea so I am missing the whole atrocity of killing sea life.
Picking up poop is not a "thing" where I live, but if there is poop in a bag, it probably is no longer mobile in the environment and putting it in a landfill for hundreds of years seems overkill, but I am a composter.