>Does anyone believe we have gained more with this "democratisation" of publishing than we are losing to conspiracy theories, hoaxes, and populism?

I do. At least now we have grass-roots conspiracy theories, hoaxes, and populism. In the past, we had top-down conspiracy theories, hoaxes, and populism.

...Top-down conspiracy theories like "Communist Hollywood infiltration".

...Top-down hoaxes like the Gulf of Tonkin.

...Top-down populism, aka, industrial-grade astroturfing.

I'll take clowns on youtube over that any day!