Characteristics that make content successful.. here again, it's mostly decent quality content plus marketing. I doubt the scripts are reviewed by NNs.

I have no idea about the network and delivery stuff, but I guess a well designed network can take care of most of it.

My strong impression is that, similar to other well known cases (Uber, WeWork) Netflix is a mostly traditional company (a media company) that very strongly wants to be seen as a tech company.

Its a bit odd that legally one can rent out physical disks, but there is no corresponding way to legally get permission to rent out streaming content without negotiating with the rightsholder. But thats how it is...