Seriously?
This journey to Teams has been a long one for Microsoft. The instant messaging was there in Exchange, then moved Live Communications Server adding voice and video. We then had Office Communication Server, Lync, Skype for Business.... for years these were bundled into the MS Office licensing and nobody really cared. Microsoft kept innovating and adapting...
It's been 20 years to get Teams where it is. It had to compete against traditional telephony brands running both analog and digital voice (Ericcson, LG), then VOIP (Mitel, Avaya, Cisco), Conferencing services from Polycom, Cisco and others... and it competes against online conferencing services such as Zoom and Google Meet. I'm sure many of you will be able to add a heap of other brands I have missed.
For many years it was a product that arguably not many people cared about. The market was probably small and I would dare say innovation was limited.
I would suggest COVID changed that with more people working from home. Suddenly this bundled extra was important. Now the market is worth more and other players want a greater share. I would suggest they are also trying to distract from their own monopolistic practices.