OK then, let's say that for every plastic bag someone uses they are charged 1 million dollars.

Do you believe that this would "price in" the cost of a plastic bag? Do you believe that, given a million dollars for every bag used, the government could clean up this supposedly irreversible damage?

I believe it could. Not only that, I believe the price would be much less than 1 million dollars.

Or how about this. Let's say they instead used that money to fix a completely different problem that is also causing permanent damage, and is equal or worse than the damage caused by plastic bags.

There is always a price. There are always trade-offs and opportunity costs.