MS are doing shitty stuff but they are hardly the monopoly they were in the 90s. You can ignore and avoid Microsoft completely if you want these days. The same is harder for Google - most people at least will want to watch something on YouTube at some point.
This is going to depend on the market. If you consider enterprise I'd argue Microsoft are very much still a monopoly. A client of mine is in the process of removing their existing telephony solution, which has many more features than teams, for teams, because teams is bundled with the necessary Microsoft 365 to get all the Azure controls needed for regulatory compliance.
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”.
Teams phone system is a significant additional licensing expense, it's definitely not 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.
