IMO, figures of authority have abused public trust to an excess.

Combined with the Internet, this has resulted in wide-spread distrust, which forms the basis for belief in false conspiracy theories.

The most easy to believe lies are those that are rooted in partial truth. Its too rich for politicans, elites, or social media giants to complain about conspiracy theories when they so regularly lie, cheat, or gain advantage behind firmly closed doors. The dissymmetry breeds mistrust.