And then you get the Replication Crisis[1], in which we find that a shockingly large number of studies in the social sciences failed to meet the bar for scientific fact.

There are plenty of "actual facts", spoken by "experts", which a few years later turn out to be absolutely false.

[1] https://en.wikipedia.org/wiki/Replication_crisis

Many people lack the necessary expertise to recognize an expert when they see one.

They thus are left to resort to authority as the proximate measure accessible to them to assess how much credit to assign to the opinions of a particular expert.

To complicate matters, there are documented cases where in the past half century at least experts have be bought by special interest groups such as big tobacco etc. This eroded public trust in any experts and many people were brought up assuming every public discourse with expert opinions is rigged. That generation now 40-50yo and their world view is having a certain weight on current matters. (Disclaimer: this is just my personal opinion, I'm not an expert. And even if I was many people wouldn't trust me anyway ;-p )

It’s easier to set up a system to provide nonpartisan funding and review of scientific work than it is to have everyone read and source all of the research.

It’s also easier to set up an apolitical body that makes recommendations based on research than it is to have everyone draw their own conclusions or devolve into “blue science” vs “red science”

These are mechanisms that cultivate public trust, and there are countries that do a pretty good job at it.

Until those apolitical bodies become institutionalized and perceived by some people as being an expression of an elite caste and then a new political current arises to galvanize people against "elites" and poasibly takes over one of the existing parties (or creates a new one, depending on the country specific political and election rules)