publish on your own site, syndicate elsewhere (POSSE) is an idea popularized by indieweb.
in short, the idea is that you should not be reliant on a platform you don't control for your main digital presence.
3rd party platforms like twitter or mastodon become funnels to your rss feed.
everything you create should live on your site, which you control completely.
through your rss feed, individuals can subscribe directly to you without the need for any of the middlemen.
%feeds was created with POSSE in mind.