I'm interested in having you expand on these thoughts, so I'll play devils advocate here. I personally don't have strong opinions on the subject.
> has proper indexes
Does it matter where in the code the index lives? Are you arguing that databases don't have proper indexes or that filesystems don't? I'm not sure I'd agree with either argument.
> correct transactions
filesystems and databases have transactions, which one is "incorrect"?
> versionstamps (for both keys and values)
filesystems have timestamps, not sure what a versionstamp is but I suspect it's some domain specific name for a more general concept that both databases and filesystems utilize.
> streaming large amounts of data
many databases stream massive data and filesystems certainly do
> all of that in a distributed database
every major PaaS has some form of distributed filesystem