Yes, this is a very poorly designed RSS feed.

500KB is horrible for RSS.

It's reasonable to have whole articles in RSS, of you aren't trying to show ads or similar.

Whole articles are reasonable.

100 articles are not reasonable.

100 articles where most of them are 1+ year old is madness.

RSS is not an archive of the entire website.

Well, its note the entire website, and i find the "last 100 articles" rule way better than "last 3" or "last 90 days" (which some times is 0 or 1).

The host is fine with sending 0.5 MiB once (the client should be aswell from both a bandwidth and storage point of view).

The host is not fine with sending 0.5 MiB every 20 minutes, which could be easily avoided if the client would use the mentioned "If-Modified-Since header".

Thanks for being someone who actually knows this stuff among all the Dunning Kruger replies

> RSS is not an archive of the entire website

Whole-article feeds end up become exactly that - a local archive of a blog.