Who says RSS is fading? Are twitter posts of years ago accessible via a simple link as are links obtained via RSS? These are honest questions and not snark.
Twitter sort of hides the RSS links, and last time I checked did not provide any documentation on how to find them. But they are there and you can access Twitter feeds via RSS once you figure out the URL pattern.
Twitter used to have a link on every public/open profile to an RSS feed of tweets. They removed the link about a year or two back. Worse yet, about a week or two ago, the feeds went dead. This used to be the feed for DEVOPS_BORAT:
https://twitter.com/statuses/user_timeline/167499429.rss
Those links have since gone dark. An alternative format still (sorta) works:
https://api.twitter.com/1/statuses/user_timeline.rss?screen_...
Per twitter devs, though, all RSS feeds are going away some time very soon. They want you reading all your tweets under their control, not in your feed reader.