A lot of discussion around RSS revolves around the format for the data/metadata (e.g. the Atom feud) but the real problem with it is this:
To consume an RSS feed you poll it. There are two polling speeds: too fast and too slow, and it's possible to be both at the same time.
Note the struggles of this Karen to turn RSS from a simple stateful protocol to a complex stated protocol, and she'll ban you if you ever reset your cache and rerun your fetcher because your cache got corrupted or you suspect it might have been corrupted.
http://rachelbythebay.com/w/2022/03/07/get/
You really want to have a stream of feed items and to be able to: (1) replay the whole stream all the way from or to the beginning and (2) query "what got added after time t?" and just get that. ActivityPub accomplishes this but people don't really like it. For Dave Winer it is all blub but even if he doesn't believe in the Fedi, he's on it.
I really like
https://superfeedr.com/
because it does all the polling for you and hits your webhook whenever a new feed item appears. My webhook is about 15 lines of Python running as a Lambda function that posts items to an SQS queue and my YOShInOn RSS reader just drains the queue at its convenience. The pricing at 10 cents/feed/month is a bargain for high volume feeds like MDPI, arXiv, and The Guardian [1] but unfortunately I can't really afford to subscribe to 2000 little blogs that post maybe once a week at that rate. I wish there were more Planets.
https://en.wikipedia.org/wiki/Planet_(software)
[1] AWS costs would be trivial in comparison even if it got out of the free tier