Content is king, as my mother who ditched Netflix for an HBO subscription could tell, despite the the HBO app and website apparently being developed by monkeys hitting keys at random. She puffs about it, but as long as she can watch the good stuff it's inconsequential. Even on Netflix most people don't mind 720p content on their 4K screen as long as they can see what's going on.
Pricing is also important.
Technology has diminishing importance after you managed to make the videos load eventually without frequent interruptions. The cost of this matters a lot, so that's what Netflix would be about as a tech company, but it would have to compete with Amazon. Netflix has it's own unique CDN, but it relies on Amazon for the rest.
