I think you go a bit too far here. Of course math theorems, scientific consensus, algorithmic inventions etc. are not up for democratic debate, they are special

I think you go a bit too far here. Of course math theorems, scientific consensus, algorithmic inventions etc. are not up for democratic debate, they are specialized subjects, to be debated among experts. However, when it comes to applying said technology to society at large, we do all need to have a say in what happens. For example, the science of nuclear physics is not up to democratic debate. But whether to nuke another nation definitely is (indirectly, via elections). And today with more and more algorithmic tracking and data analysis it is de facto up to tech companies to decide in what ways the deeply impact society without our consent. Yes, measuring the performance of a classifier from different aspects, with different metrics and optimizing it with novel techniques is not the job of the public. But deciding whether we allow an all-encompassing social credit system that assigns you "sentiment scores", tries to guess your level of narcissism and sociopathy and recklessness based on your Uber data or emails or Airbnb feedbacks etc. definitely is. "We're not yet there", you say. I say, give it some time. If it's up to businesses we will arrive there. The only way around it is the democratic process you despise.