> but surely consumer SSDs wouldn't just completely ignore fsync and blatantly lie that the data has been persisted?

That doesn't even help if fsync() doesn't do what developers expect: https://danluu.com/fsyncgate/

I think this was the blog post that had a bunch more stuff that can go wrong too: https://danluu.com/deconstruct-files/

But basically fsync itself (sometimes) has dubious behaviour, then OS on top of kernel handles it dubiously, and then even on top of that most databases can ignore fsync erroring (and lie that the data was written properly)

So... yes.