There are millions of applications with their own upsides and downsides. Focus on some of the ones with big downsides and easier replacements. Shopping bags, for example, would be easy. Car tires are hard. One thing that might help is to take money from the benefits and use it to offset the costs. Subsidize canvas bags. Tax car tires and use the money to research microplastic recovery tech like https://news.ycombinator.com/item?id=25246857