In actual fact -- not a thought experiment at all -- we now negotiate our trade agreements in the interests of investors and global companies. They prioritized their interests: higher profit margins, "flexibility" to do what they want, maximum possible trade, and a shield against local, regional or national policies that might reduce their economic prospects.
They actually do use the WTO and various trade tribunals to enforce investor interests, independent of any national courts or political accountability. The global economy can grow and produce great wealth. And to be sure, this is no mean feat.
Economic growth could arguably align with public interest, at least in a trickle down sort of way. Please hold your fire on this one, for a moment."
One may not entirely agree with the analysis out there, but some food for thought? Are trade agreements only exposition of business interests and not "national" or "public interests"? It brings us back tot he question of what interests the state represents as well as the multiplicity of stakeholder interests.