Earlier quoted context omitted.
This is an excuse to be lazy and not try to establish truth at all, which is way worse than getting the 'truth' wrong sometimes.
I think this is the core political question of our age, myself.
I am starting to think that ultimately, though, the answer is one that no one particularly wants to admit because it boils down to two unpalatable options, one distributed and unregulated; the other centralized and regulated.
1) Unregulated: No one is the arbiter of truth, in which case a haphazard group of marketers, propagandists and psyops peddlers reign supreme. This eventually/inevitably consolidates into an organized propaganda outlet.
2) Regulated: A group is selected based on some credential or merit and you end up with essentially a Technocracy. More or less what the "Elites" boogeyman is. If the Technocracy is staffed by scientists and engineers, then it might be the best possibility available. But this also eventually consolidates and leads to an erosion of the eligibility credentials and then non-expert people will gain positions within it for ulterior motives.
If the technocratic group is limited in scope of what "truths" it can decide on, then that is potentially a reasonable compromise.