I'm just an engineer with no background in finance, but didn't a fair part of the 2008 collapse come about by trusted third party risk auditing that went bad? Rather than maintaining a centrality of trust at some level, it seems intuitive that if there is a public database with trust decentralized among all the participants, there is less of a chance for that trust to be abused.

Financial transparency and integrity is a wonderful goal. However, I am yet to understand why any kind of blockchain is necessary or sufficient, or even a good solution. If you want to cook the books you can do it with or without blockchain. Same if you want to be honest. Blockchain seems like a very complex and expensive way of persisting transactions in a database.

It’s just a fundamental naïveté about how the world works. If I’m dodging taxes or hiding profits then I’ll just enter false numbers on the blockchain. Now what good is the blockchain?

Or I sell you a plot of land and mark it on the blockchain but then bribe the local officials and keep the plot to myself. But but muh blockchain says it’s mine

The "risk auditing" was the bad part, and that's a human problem; writing those decisions to a different kind of database wouldn't have helped in the slightest.

Not in a way that would have been impacted by a blockchain ledger. Third party risk auditors were giving financial products risk ratings that were far out of touch with their actual risk levels. But this was due to flawed logic, financial incentives, and corruption, and not because of a lack of transparency. The data of the mortgages comprising these financial products was available to those interested in those looking to fact check, but no one was.

Except those guys who shorted it. There was even a movie made about it.

Efficiently? Maybe. Providing the same type trust and guarantees? Probably not. A public, append-only Merkle tree just has a lot of interesting properties and I think there are spaces where they are useful.