As throwawayswede said, people are still using this technology and to my opinion, that is still active. There are a lot of things that are using RSS, it is not oblivious to us which why people believe it is dead.
Yes, RSS specification haven't made any improvement since 2010ish. However, the community are still using this technology. It honestly blew my mind that it is still around when I decided to go back to RSS few months ago. The community have developed various tools to make RSS amazing to use. There is RSS-Bridge (souped up RSS on steroid), RSSHub, RSS.app, Feedburner, FetchRSS, etc. RSS readers and it tools are still active and making improvement.