Microsoft Teams, Skype, VS Code, Internet Explorer, System Center. Not sure you could argue these are non-business applications, and none of them seem very consistent to me.
Interesting point, but that wasn't my experience. The office suite was consistent, but SharePoint differed markedly (at least in ~2010 when I last used it). IIS was different yet. I'm trying to think of other business-oriented MS products that I used (it's been a while)...