Featured articles were fairly popular when they were around, actually. There was a rating system for it and everything, it was pretty useful. 5 star articles used to be pretty smart. But they switched to the new design for the sake of change, and made everything completely white, added like 35 topics instead of the original 6, decreased Xper rewards, removed stories, removed ratings on questions, removed reality check, removed chat, and most of the new "updates" where they aren't just messing things up they are just recreating functionalities this site used to have.
We're currently not accepting new article submissions, but we will again in the future and will keep you guys updated on that. As for how popular they are, that really depends on the topic and the article itself. Some are very popular, still being commented on and discussed today (months, sometimes years, after being written). For those who haven't seen any, they can be found by going to QUESTIONS at the top, clicking By Topic. Once there, select a topic... then click Articles from the topic page.