I guess Microsoft lost this battle, at least at some companies, because I'm now at one that uses Slack and Google, with no dependency on Microsoft Office.
Teams was clearly never meant to be used as a standalone product. It was a pretty effective defense play. Block other competitors from gaining a foothold.
Thats the whole point. The only people using Teams are the ones who are already committed to Microsoft 365. Companies on GSuite mostly use Slack, I doubt there is a single one using Teams.
Microsoft won this battle if you check the numbers. Last I saw it was 85% Microsoft vs 15% Google which seems right with my experience. Current company is Google Worksapce while last 3 were Office365.