It's mind-boggling to me that something as nebulous and tradition-over-proof-oriented as the concept of a "prestigious journal" still gets to be the centerpiece

It's mind-boggling to me that something as nebulous and tradition-over-proof-oriented as the concept of a "prestigious journal" still gets to be the centerpiece of the functioning of the entire scientific community. I get that we need some way to measure "scientific success" when awarding grants and tenure, and published articles fit that bill. Which means we need a way to validate "real" journals to avoid abuse. But the fact that it's something as vague as "prestige" or "respect" that is the defining characteristic of those journals, I don't get that at all, not in this day and age. It's not "has process X, Y and Z in place to make sure their articles are up to snuff" (e.g. "original data is available for independent review"). It's not "has their processes audited by independent agency A". No, it's just "brand value", it's "they've been doing this for a while, and a lot of people believe in them, so we'll just take on faith that whatever they're doing is good enough". How very scientific...