One key benefit of putting up an own server is that there are no limitations on file types and much fewer restrictions on what kind of content you can create.

For serving static files, I can (and have) lived a long time with one of the "free hoster" sites -- from times before Github Pages or S3 were a thing I guess, today I'd go for Github Pages.

A key advantage of moving to an own server was that I can enable the odd feature or technology any time. E.g. most recently I wanted to have some "private" subspace with fancy authentication and it was easy to add with proper access to the server config.