If you loved a writer’s output of x but couldn’t abide their output of y, no problem — you’d just suck their feed into your reader and tell it to block stuff tagged as y.
That dream is mostly dead. Even on the Fediverse, your ability to follow someone for x but not y is crude as hell, hardly better than the web of the early 2000s.
Personally, what I find interesting about Doctorow’s discussion is whether you find a writer or are just interested in a topic. Although I am really intrigued by Chris Aldrich’s model, where you can easily put together a custom feed of the bits you you like. I fear that this sort of model still puts too my onus on the writer, not the reader. I also feel that maybe there is something of a reality of going crate digging. Maybe, feed readers will continue to evolve and become ‘smart’, but for now I will live with the practice of serendipitously sifting and sorting through feeds for the dots.