Eric Weinstein can be long-winded with a hell of a lot of setup.  It took me an hour to come to the realization of what he is speculating (I think) which I will summarize for you thusly:

1. Breakthroughs in physics are dangerous to humanity
2. The breakthrough that combines quantum and gravity will give someone enormous power
3. Edward Witten is very odd, crazy smart, and seems to have directed everybody towards a dead end, possibly to save us by preventing the next breakthrough.