The selling point of original Skype was that it allowed making audio calls on worst connections, requiring just several kilobytes/sec, and going through NATs (other products required a direct fast connection and were usable only within a local network). As for P2P, I don't think users care about that. Not having P2P is actually better because P2P can disclose your IP address.
For example, Tox is a fully decentralized P2P messenger and it is not widely popular.