I’m not sure I understand, there are still plenty of sites with RSS Feeds, native or via 3rd parties (OpenRSS, RSSHub, nitter, proxigram).

And for those websites without them, scrapping to RSS is (IMHO) the easiest solution. See pipes.digital.

Anything with similar functionality would need to reinvent the wheel and implement the same features that RSS has.

But maybe I’m missing something…

I have a script to copy the RSS feeds to my mailbox using IMAP running as a cronjob. When I decided to do it I even found a few open source solutions, but I ended up doing my own because I wanted to fine tune it to my workflow.