Not to downplay the tech, but you could replicate majority of the tech nowadays with proper engineering effort, proper timeline and a budget. YouTube competitor would need to beat them in the business side of things, which is extremely hard, however not unachievable. The company would need to have proper monetization, proper support with proper appeal system and to enable producers to create high quality content without the fear of their accounts being banned. I believe this would be sufficient enough to start making a dent in the YouTube creator base.