For the same reason we spent a year testing COVID vaccines. You don't want to put something of unknown effect into your body. You especially don't want to put s

For the same reason we spent a year testing COVID vaccines. You don't want to put something of unknown effect into your body. You especially don't want to put something unknown into everyone's body all at once. It's not "good vs. bad" it's "safe vs. not safe". It's also about emergent properties that aren't apparent until you've hit a certain scale. Fish with plastic heavy diets have more tumors and liver problems. It would be pretty shocking if there wasn't an inflection point at which we see some heavy consequences for humans as well in terms of plastic concentration. Maybe we won't reach that level practically for a long time, maybe we will. I lean towards thinking we won't see too drastic of a consequence in the next 200 years (not backed up by anything) but I'd still say it's definitively a problem.