They never had a monetization plan and don't charge for use and their last re-design was in 2012? How do you think they make money? Either they don't and they are going to disappear soon or they do and they are just another data pimp.
They got bought by Skype awhile back which is being shelved in favor of Teams. I bet MSFT shuts it down once it remembers it still exists.
Skype for Business, which is not Skype at all, is being shelved in favor of Teams.