I totally see Microsoft ruining TikTok simply because of their corporate culture. Microsoft has had an astonishing history of destroying billions of dollars in value simply because they can't manage their products better. Internet Explorer, Bing and their mobile phones represent entire industries where Microsoft has been totally decimated despite enormous advantages in terms of resources and monopolies.
Your criticism is that Microsoft isn't a $5+ trillion company, doesn't have five plus monopolies (desktop OS, mobile, browsers, search, and a few others that would go along with those positions including advertising), and basically isn't all knowing and all powerful.
What you're projecting is impossible of course. No company could ever accomplish all of those things. What you're holding up as a supposed indication of incompetence, is in fact unavoidable: failure will happen, you will not always win, your products will not always succeed, and most likely you will fail the majority of the time; it doesn't matter who you are, or how big you are.