There is this problem that RSS is a poorly designed protocol that has two polling speeds: too fast and too slow, and sometimes you can be both at the same time.

If it was truly a stateless protocol it would be a simple protocol, but if you want proper caching or rate limiting it is not a simple protocol at all. I mean, browser caches work right in web browsers in 2026 but it took 2 decades to get that far and today there are only three organizations in the world that are capable of delivering a workable web browser.

But RSS is blub and you could never convince an RSS advocate that ActivityPub solves a problem worth solving (with its own problems, not least not being such a "simple" protocol)