It wasn’t that they destroyed it, it was more that they let it bit rot. Skype was honestly never a great user experience by today’s standards. The audio was bad, the connection was very unstable over mobile networks, and push notifications for calls was hit or miss. Microsoft acquired it, slapped a Microsoft login screen on it and then basically didn’t do anything to improve it. Meanwhile, Google created and killed seventy different video calling apps, which all worked better than Skype, and Apple stuck the landing with FaceTime.