Why does TeamSpeak copy Discord?

I know that Discord and Teamspeak have different type of server mechanics - Discord = cloud, Teamspeak = classic server type. I am talking about application appearance/behavior that is very simmilar. If developers dont like that comparition why they make TS5 design like Discord copy? Like I said I dont like Discord! But if the TS5 is the same design there is no reason to use Teamspeak right? I mean why should some regular user use Teamspeak?
Just to be clear! I mean the app GUI and behavior. Some speacial features are minor for majority of people.