I'm a half-way house person when it comes to CMSes and databases. I don't think raw content needs to go in the database, it can happily live on the file system (assuming a sane permissions regime) and you can delegate version management to git.

However I feel metadata and other structured data belongs in the database for the usual reason: to support unforeseen future queries. That is, to make plugins and widgets easier to develop and better performing (vs, for example, iterating over every post or every comment to perform some calculation).