Foreign propaganda in democracies is as old as democracies themselves. It is by no means anything new; foreign influence campaigns spent enormous sums and labor trying to sway democracies from the very beginning - often very successfully. I don’t see why it’s any different for it to be published on Facebook instead of laundered through print media and rumor mills. At the end of the day you either recognize these problems and appreciate that trusting your electorate/having a liberal democracy is the best option we have compared with the alternatives…or you don’t.
Many of those democracies are trending illiberal thanks to the useless yet arrogant liberal decrying of “there’s simply nothing else we can do” and championing a rotting status quo.
Several western countries could kill their more extreme parties overnight simply by enacting a few reforms with immigration and/or affordability.