It was fantastic for the readers, but it did not have a sustainable businessmodel for the producers. Not enough eyeballs on the actual add stuffed sites when you can just grab the content straight.
So Google set out to absolutely dominate the the RSS client space with their free Reader. They succeeded, then just terminated the product. And that was for many the end of the line.
I have loads of RSS feeds and I almost universally use them as notifications to go and see the post on the full site.
Most RSS readers I'm aware of prominently include an option to view the full page, often inside the same app (and these apps are less likely to have content-blocking add-ons installed, which would block lucrative surveillance).
I'm quite happy for RSS feeds to include only a summary/thumbnail/excerpt plus a link to the full page.
So Google set out to absolutely dominate the the RSS client space with their free Reader. They succeeded, then just terminated the product. And that was for many the end of the line.