Regulatory capture is indeed a major underlying cause of a lot of the issues, but who will actually do the political work to fight against it? Someone spent money to capture the regulations in the first place, through lobbying and campaign donations. Who will spend the money to lobby and donate for the cause of undoing that?

The "builders"? No, their focus and limited capital is spent on whatever it is they are working on.

The most logical choice would be the investor class who supports such work. After all, these regulations create legal risk (from lawsuits/fines/regulators) for the ventures they fund. It also makes employees more expensive (through higher housing/education/medical costs), thus requiring more investment just to get a venture going. Yet, why is there no real, funded, concerted effort against regulatory capture? Just essays and talk?

I suspect two potential reasons:

(1) Opening regulations would help all current and future ventures, not just an investor's own portfolio, so no single investor has an incentive to do it by them self.

(2) Such investors are typically wealthy, and spending money to tear down regulatory capture that other wealthy people already paid for would be... uncomfortable. Such spending could be seen as indirectly attacking friends, relatives, college classmates, etc... No one wants to be labeled a class traitor.