Lead and asbestos in housing and consumer products were similarly intractable, but we (mostly) banned them anyway. We're still dealing with removal and mitigation decades later, but at least those problem aren't getting any worse. At some point you have to say enough is enough and ban plastics in contexts where they're most likely to find pathways into the biosphere: food containers, disposable goods, clothes, car tires, water pipes, etc. Just because the problem will take centuries to resolve doesn't mean that we can't start now.