There may be examples of protecting the public good being propaganda designed to hide the reality of using regulation to protect a minority interest. But there are also countless examples of true public good objectives being served by regulation.
One example is environmental dumping regulation. Unregulated release of chemicals into the environment by a minority harms everyone. In north Carolina entire watersheds are polluted with forever chemicals because the power company was dumping transformers in rivers. Now no one can eat fish.
I am not saying we shouldn't have an electric grid. But clearly their unregulated right to dispose of transformers is in their direct economic interests and against the public interest. And clear simple regulation can support better development with reduced harm.
I dont follow your example and am not familiar with that issue. But I would be the first to acknowledge regulatory process can be abused and irrational but that doesn't mean it is always bad or worse that other approaches.
I agree with you that regulation should have a cost benefit analysis. I would remind you that it often does, look at the public comment process, congressional debate, judicial opinions where that analysis is done in public view.
I would argue that there are improvements to be made like requirements to make predictions on the effects of a regulation and a sunset if the predictions don't match outcomes and a mandatory sunset of all regulation based on time and changed circumstances.
But I would rather have the government regulatory process than anthropic, or Facebook, or Uber or cursor being able to change their terms of service to implement adaptive pricing or training on my data or making digital clones of my family and using them to advertise in misleading endorsements.