He stole the idea and concept of the twins - sure he took it further along but the strategy etc was stolen.
Then during the high-growth phase of FB, he relied on a team of individuals who cared nothing but running scientific experiments with large amounts of data - again nothing he did there.
The IG and Whatsapp Acquisitions? I mean when you have all that insider knowledge (years of deep knowledge of the product space), it was an inevitable ploy to acquire a monopoly at whatever price - serving billions of people at scale was always going to lead to tremendous cash flows.
He brought in Sheryl to run the show w.r.t forming the business model and operations.