Yes, which is why they'd have a interest in publishing studies that make bag bans look useless or counterproductive, because they want to persuade people not to pass or to repeal bans.
Maybe the narrative is obscuring something with statistics. If reusable doesn't really make plastic use go up, and that bag bans are effective in reducing plastic use, the industry opposing them has an incentive to make it look like they are ineffective. They're using the same tactics the tobacco industry used to counter the facts about cigarettes.