I've been railing about all the spying Microsoft Teams is doing across corporate networks for the last year or so, to nothing but shrugs, 'I'm sure Microsoft isn't using our business data' or similar responses. People never learn.
I suspect that the kind of company that uses Teams is just not very interested in critically evaluating Microsoft or competitors (relative to companies that are evaluating specific Microsoft products as one-offs). They're already bought into an ecosystem whose main strength as a collection of mediocre (or worse) software is that it is integrated with all the other mediocre software in the collection. If they don't 'trust Microsoft', where does that leave them? So they 'trust Microsoft', and that's the end of that.
For example, if Bob at ABC Company is working on an MS Word doc, yes, Microsoft can steal that data. But it's worse when Teams is on a corporate network, because maybe Bob has a Teams meeting, pulls up the Word doc, discusses it with coworkers Sarah and Bill, and now Teams tracks the doc, the conversation, who was in the conversation and what the conversation was about. It tracks the email conversation that follows. All of this is proprietary information. Teams has handed Microsoft the internal working projects, context, thoughts and strategy of ABC Company.