I think there are different levels of challenges to act on. From a grassroots level we could engage society in the problem, by making it visible on actions such as clean ups and talks in schools or community events (that could highlight the consequences of marine litter and practical changes in habits of consumption to tackle this).
It would also be important to approach key organizations such as fishing associations to promote awareness, as fishing gear represents a large part of marine litter.
Policy makers should be also be involved/aware of these actions, as they will begin to change policies when they feel they have public opinion consent to prioritize the environment, sometimes at the expense of (short term) economy.
And yes, for the new generations, so connected to the social media culture of positive and fast content, it would help to have influencers communicating this in a way that is more appealing.