That’s true, but it could still be more specific.

For example there’s a comment about symlinks on exFAT. Steam could say “failed to create symbolic link” instead of “disk write error” in that case.

There typically are a few different error conditions for normal writes too that Steam could pass on. E.g. on Linux there are separate errors for out of quota, files becoming too large for the fs they’re on, the fs being out of space, and low-level I/O errors.