The issue is a ton of companies already had Office subscriptions. Versus Teams being an added cost, so its a no brainer to just go "Well why the heck do we need Slack if we are getting Teams at no additional cost?" and now any startup in said space is competing against Office proper, which is a losing battle and a lot of added requirements to get your product off the ground.

If I were Microsoft I'd reconsider bundling Loop, since it's going to disrupt tools like Notion. I mean, why would I bother using Notion, if I can just use Loop? : - )