Replied to a tweet by Mariko Kosaka (Twitter)

I see some of you here are moving to RSS and blogs. I never understood trackbacks in Web2.0 days, are we still gonna use it and can someone explain it to me?— Mariko Kosaka (@kosamari) August 10, 2018

https://platform.twitter.com/widgets.js

Webmention is the more modern specification now as some have mentioned. I wrote a piece on it in @alistapart recently which includes some background, UI examples, and links to more technical resources:
https://alistapart.com/article/webmentions-enabling-better-communication-on-the-internet
It is a small part of an #IndieWeb suite of open protocols including Micropub, WebSub, and Microsub for allowing site to site communication and interaction which goes to the broader scope of your question about RSS feeds and blogs. See also: Lost Infrastructure
I keep meaning to provide a better overview of it all, but this recent pencast overview captures a chunk of it. Aaron Parecki’s article Building an IndieWeb Reader captures some of the rest of the microsub/reader portion.