Don’t know what’s hard to understand there? Microsoft didn’t have a chat product (worth anything, Skype was a mountain of crap). Slack comes along and builds a great product, Microsoft goes “oh, the office suite now includes teams!” So everyone gets it “for free” if they have the office suite, murdering slack in the market. And of cause everyone will have to pay for Teams as the price of the office package rises to I cover the costs, no free lunch and all that.
It had been a different story if Teams had always been a part of office, and slack came along and tried to compete. But come on this is a 100% clear cut abuse of a monopoly on windows office programs by Microsoft abused to outcompete a competitor that they couldn’t fight honestly.