Perfect can be the enemy of good. At least on the east coast, smog was improved considerably when the coal plants were finally allowed to update to newer tech.

Perfect can be the enemy of good. At least on the east coast, smog was improved considerably when the coal plants were finally allowed to update to newer tech. The owners had wanted to update their plants for several years, but the EPA was preventing them from doing that unless they met an unrealistic target. So the plants continued to unnecessarily spew pollution because of the standoff. The EPA was finally overruled and the updates got the coal plants to about 95% of what the EPA wanted.