The use case I have in mind: say for example, I read a lot of articles about a certain topic, such as Linux or chemistry or whatever. I want to combine the articles I write into a singular feed, and for others to be able to follow it. Call it "Alex's Linux Feed".

Another use case: Suppose I follow a news source (like washington post), but maybe I dont like the formatting of their feed. Maybe it does not have the full article, or maybe it is not organized right (sports news is mixed with political news, and I want to separate them right). So I create my own feed where I organize those same posts better.

The reason this would be a platform because the user should not be burdened with hosting it (even if it is not difficult), and it should be searchable.

Is there any platform like this of user created RSS feeds?