This is a good one because the most likely outcome of this is that the fungus spreads to all plastics, not just the waste in the ocean, and soon your household items are getting eaten.
It would be funny for there to be a massive sewage management issue in every major population center, at least
Overall though, maybe we shouldn’t be relying on pipes that slowly poison the environment through the slow shedding of microplastics anyways. As ridiculously painful as the transition would be in this case