What we do know is that finding academic fraud is like shooting fish in a barrel. It's way too easy even for totally unfunded volunteers. The situation in science right now is reminiscent of the situation in computer security circa 1999. Back then there were so many easily exploited RCE vulns in foundational infrastructure that "hacked by teenagers" became a TV trope. Almost anyone could sit down and find a way to hack into a network without much effort. Vendors engaged in a lot of screaming and denial, sometimes even attacking the people who found exploits for them.
But, the industry changed. White hats became widespread, companies hired those ex-teenage hackers in their thousands. They put every employee through trainings. Then when that wasn't enough they started paying out millions in bug bounties, buying sandboxing companies (like Google did for Chrome) and more. Companies did this because bad security was hurting their reputations and in a competitive market that is an exploitable weakness. It was a form of self defense.
Academic science is excluded from market mechanisms by legal fiat, supposedly on the basis that this will yield better research outcomes. What it's actually done is shield universities from any need to make hard changes. Their reputation is tanking but they just don't seem to care and why should they? They'll get grants from the NIH anyway because they're all as bad as each other, and nobody in politics is talking about a total defunding of the sector yet.
Unfortunately even if the grants were cut off tomorrow they probably would still find it hard to change. It's becoming apparent that if a culture tolerates fraud for decades then eventually the leadership of these institutions are people who got there through fraud. How are universities or journals going to reform when the people who run them know full well they can't crack down on fraud without exposing their own career to audit risk?