It’s important to read the whole article. I’ve never claimed a rug was a solution to everything. If you’ve read my posts on acoustics I often talk about having a minimum critical mass before room treatments become audible, including first reflection points. That still applies here.
Darko’s article doesn’t say rugs aren’t helpful, but that they are limited in effectiveness. That’s different. Also, the point I wanted to say here was a little different and dealing with a small overlooked corner of the room behind the speakers. Fortunately I’m not asking anyone to spend money. Throw a rug or blanket behind the speakers and see if you hear a worthwhile improvement. If so, maybe get a panel for that area.
Specifically Darko does not say "don't put a rug on your floor it's useless." He only points out how limited its effect it is in light of other treatments. You'd be foolish to NOT put a rug down if you have a bare wooden floor.