Cant read the article due to paywall, but, nothing "went wrong" with skype, it was and has always been utter trash. Just having your username leaked was a security breach. Skype's only merit was it was the first easy to use video calling platform that combined text, audio and streaming in one.
Theres a reason why it was so easy to move my friends group off skype to discord right when discord launched, but I havent been able to convince that same group to move from discord.
My memory says that both vent and teamspeak were way better for audio, but this was also a time where no one had a mic remotely close to the average you get today. Video, yes. But skype was really buggy and often did not even work