Maintaining tags for all rss feeds is cumbersome using the regular
flat list where there is no hierarchy and tag names are duplicated
a lot.  Org-mode makes the book keeping of tags and feeds much
easier.  Tags get inherited from parent headlines.  Multiple files
can be specified to separate your private from your work feeds for
example.  You may also use tagging rules to tag feeds by entry-title
keywords.  See https://github.com/remyhonig/elfeed-org for usage.