It's like a modern religion, with three tenets: (1) science made everything around us (iPhones and airplanes!) (2) we speak for science (3) therefore you must believe our conclusions.
But in fact, that's the opposite of a proper scientific attitude, which always admits doubt, and believes experiment over authority.
As for why authorities are increasingly losing trust, I think it's because they've been rather unreliable recently.
To use just one glaring example, the official advice on masks went overnight from, "they're useless!" to "you're killing people if you don't use them!".
Both positions were condescendingly presented as "the science". A lot of people will start to lose trust when you so glaringly contradict yourself in such a rapid amount of time.
In general, the approach seems to be when crafting public advice to not worry about presenting an accurate picture of our current knowledge, but just pick a position, pretend we are certain it is true, and hand it down as the infallible words of Science. (See also: our ever changing dietary recommendations.)