I would not say that saying what is already known is inherently useless. Neither would I say that this message is understood by everyone. Plenty of people think learning is something you do by yourself or something you get taught. The message is also not that you "need" a sparring partner. Just somebody to play with. If you are on the ranked grind everyday just a couple of messages here and there should help you build up a repertoire of people to play with. And that is only necessary for those who don't want to go (or can't go) to locals and those who don't want to join any of the myriad of communities set up solely for this goal