Oh, it can... OCS / Lync / SfB was a nightmare. Compared to that Teams is App of the Year. Which is saying a lot because Teams is definitely not "good". It is "good enough" though, IMO.
As someone who used office communicator back in 2006/2007 time period, it felt more snappy and consistent than anything that came afterwards. It was simple and basic as hell, but didn't have all the quirks.