That may be so, but my group of 4 has been using it for voice, text, and screen share, with almost zero issues. (Except a couple sync issues that fixed itself in a day) We are working on getting off the matrix.org server soon though.
I'm surprised actually how good its been. I am sure the small glitch we had is because we are on matrix.org. need to move soon. My friend set up our room without me and didn't understand that you don't just use the matrix.org server ...explaining how matrix works is hard to non nerds.