It's not bundled is it? Functionality comes with the licence. For example our teams usage is dependant on our Office 365 E5 licencing, which costs money. Word comes bundled with office yet no complaints. Google spreadsheet comes bundled with google workspace.
It's also got native integrations with SharePoint, Azure, windows and anything Microsoft. And even then the functionality and user experience is alot better than the competitors. I hate WebEx with a passion.
Whether or not the software is good or not (I personally can't stand Teams) is not relevant. It's about whether a company is using its present market dominance to shoehorn itself into a new product segment. Teams is available by default in most o365 packages
In General, using a part of your business that's on top to boost another part of your business that is not is typically seen as anti-competitive. Office is clearly the market leader, but Teams isn't.
IMO, the EU needs to do with Edge and Office. There is now a toggle in Outlook that ignores your default browser and opens everything in Edge. It's ridiculous.