- News sites like HN or LWN, where I find the RSS experience quite suboptimal compared to participating directly.
- Blogs, which I read entirely via Planet aggregators: Planet Debian, Planet GNOME, Kernel Planet, and Planet Mozilla.
- Comics, serialized stories, and other things where I want to read every page and remember what I haven't read. For these, I use Comic Rocket (https://www.comic-rocket.com/), which a friend and I wrote years ago. Every one of the comics you mentioned is tracked there, along with XKCD's What If.
(That's in addition to mailing lists, which includes announcement lists, and Twitter, which also covers things like This Week In Rust.)