There appear to still be many people still using RSS feeds, but RSS feeds are really a tool for the end user. It basically allows users to be able to download your content without having to go through the trouble of actually using your website. They can just read your feed for any content you post on your site. The content goes right to them without the need for users to revisit your site. It is also a great tool for other sites to steal your content and republishing it with ease. They don't have to go through the hassle of viewing to your website to cut and paste your content. Again it goes right to them.
From a webmaster's stand point, you generally want people coming to your website. You want people submitting vulnerabilities to your website to make your website more successful. Implementing RSS feeds does not provide you any of that benefit other than potentially the notification of new content on your site. However those users still do not need to go to your website to view it. If you are planning on making revenue from people viewing your site, every RSS feed is a revenue loss.
I view it as my website is the news reader, go to my website to view my news. Google will take care of the rest. If the question is if people still use RSS, yes they do.. But if the question is if this provides your site any benefit, then generally it does not in my opinion. I would rather people go directly to my site.
/news/index.html
,/news/index.rss
,/news/index.json
, etc.). It shouldn't take more than 15 minutes to do all of this.