The fat slow company is like that because thousands of C-teamers are weighing down the 100 A-teamers. Whether it becomes lean and fast after terminations depends on how accurately you're able to isolate the C-teamers and remove them.
Oh yes this is the real issue... Do you really think they hired a bunch of C-teamers? Give it a break...
Yes. Most people cannot code or manage. They puffed up their resume, copy and pasted someone else's work, and presented well. Therefore they got the job. That's how the game works. It's not about what you know.
You think code or manage is the only way a social media company works? What about content policy? What about sales (you know, the thing that lays the bills)?
Despite it being cliche, that is my experience. Most people don't add much value either because they lack the competence or they're lazy.