Feeds still have a lot of inertia, at least. Most blogs generate them out of the box, and Wordpress being as predominant as it still is means you can still find them even where you don't expect to. Even social media profiles can compress into feeds with a little help from solutions like Nitter (or in Bluesky's case, offered natively). What I think is really missed is the social component that Reader had, which you still can't really find even with the variety of great readers that came in its wake.

I know I will probably just migrate them to RSSHub when the time calls, but YouTube's channel and playlist feeds have been such a great way to follow a large number of creators. I'm still holding my breath for the day they unceremoniously stop working.