Matthew Wilcox [off-list ref] wrote:

Filesystems should not make an assumption about this ... I suspect
the optimum page size scales with I/O bandwidth; taking PCI bandwidth
as a reasonable proxy, it's doubled five times in twenty years.

There are a lot more factors than you make out.  Local caching, content
crypto, transport crypto, cost of setting up RPC calls, compounding calls to
multiple servers.

David