There was a time when Skyping was so popular it became the generic term for video chatting. But the more MS fiddle with the UI the more people now realise that there are better alternatives out there and they have lost a vast amount of users to other messaging apps.
I still use it to chat to my elderly parents, but they get annoyed with it because MS keep 'improving' the UI and they have to work out how to use it all over again after it updated to the latest version.