I know successful companies (and the VCs that back them) look for large market inefficiencies, which create profit opportunity. I wonder if anyone has ever broken down their profit opportunity in terms of: (1) we're taking advantage of this existing inefficiency and (2) we're creating these externalities that we don't bear the cost of.

Some investors would not be dissuaded by (2), if they are purely looking for financial returns. In fact, if you could make a compelling argument that you're externalizing some of your costs, it could be attractive to financial investors because it would help prove that your business model can be profitable.