> that doesn't explain the deliberate kneecapping of R&D, health, and academia

I think it does, those are all efforts to destroy trust in qualified experts. It's impossible for everyone to understand everything, so we have to trust experts. But the experts correctly point out that Republican policies are actually harmful to their own voters. So, Republican media bought into a ton of conspiracy theories, which are centered around exploiting difficult-to-understand systems and promoting "do your own research" type conspiratorial thinking. Once your voters no longer trust the experts, you can sell them anything you want, namely policies that move wealth from the poor to the wealthy.