The basis is in what they experienced in their past. That made the story they told themselves. Whatever one finds on tv, radio on internet that confirms that is true, the rest is false. I think the neo-liberal of a retreating government, privatised institutions and a growing inequality between the haves and dont haves is what formed the foundations of today's declining trust in that same government. So covid stands not in itself, but rather brings up underlaying currents which where already there.
I don't see anyone freaking out about covid and accepting the lockdowns and mandates without a lot of nudging and hectoring from media, whose messaging which we now know was largely shaped by government officials who have connections to industry. I think you and I have a lot of overlap - the main difference being that you see government and private entities as two different institutions. Sadly, at this point I see most government agencies as an extension of private interest. At least in the US, corporations write the policy legislation which creates both regulations and subsidies that are favorable to them. The resulting spending not only directly increases wealth disparities, it also leads to more inflation which exacerbates those same inequalities.