These technologies undermine authority but strengthen authoritarianism.
It will bring trouble to authorities and consensus that are not very authoritarian (e.g:EU vs Brexit, the polarization of politics leading to populism, gridlock and inaction in some democratic countries, the increase in brain drain from less developed countries, etc).
But, OTOH, very authoritarian regimes are clearly very capable of taming the internet (e.g: Russia, China) and harnessing it for their own propaganda and control.