Most enterprise organisations killed off their different chat clients and phones and switched to teams in my area of the world. Not necessarily tech companies, but everyone else didn’t want the additional cost when Teams came “for free”.
It's also not standards compliant, despite speaking a malformed version of SIP, so you can't just plug it into standard SIP Infrastructure and have it send and receive invites for calls, or send and receive SIP simple messages for texting.
I've never looked at the cost, but I was told switching to teams is being done to save money. So perhaps not as much money as hoped...