Rant time.

The user experience of Skype was only the beginnings of the nightmare. Managing Skype for Business from an administrative perspective was miserable and it was clear that the back end was just a horrifying amalgamation of repurposed old Microsoft projects like Lync and MSN Messenger. They literally just slapped the Skype brand name on their own stuff and tried to make it work only to scrap it all and rebrand it again a few years later with Teams. Classic Microsoft.