Hidden volumes solve for any type of coerced decryption.

I can use Tahoe-LAFS for personal backup and it'll be encrypted, but
it wont have ORAM. Most academic work on ORAM is in the context of a
centralized cloud service provider. ORAM was not invented in absence
of a threat, but it may be applied to a system with no benefit.

Here's an example statement from https://arxiv.org/pdf/1605.09779.pdf
"ObliviSync: Practical Oblivious File Backup and Synchronization"

"ORAM is a powerful tool that solves a critical problem in cloud
security. Consider a hospital which uses cloud storage to backup their
patient records. Even if the records are properly encrypted, an
untrusted server that observes which patient files are modified will
learn sensitive medical information about those patients. They will
certainly learn that the patient has visited the hospital recently,
but also may learn things like whether the patient had imaging tests
done based on how large the file is that is updated. Moreover, they
might learn for instance that a patient has cancer after seeing an
oncologist update their records. This type of inference, and more, can
be done despite the fact that the records themselves are encrypted
because the access pattern to the storage is not hidden".

Karl, pleasure writing to you, I hope you understand a bit better why
I'm asking about ORAM-FS's benefits.