I dunno, Skype allowed Microsoft a quick platform to have a VOIP solution for maybe 1 years, and they started to leverage that in Skype for Business in 2016/17 or so, before Teams was really ready.

My company moved wholesale from an Avaya VOIP solution to Skype for Business (Lynx) for about 5 years four that capability, before flipping chat & collaboration to Teams. The Skype phone solution was kept until 2023, I believe.

They definitely squandered what Skype could have been, though, definitely could have done more and made it a strong alternate to WhatsApp and the like… they had something like 1/2 a billion user accounts at one point.