When I worked there the product team at Netflix had two KPIs all new features were tested against: hours watched and retention. We would come up with all sorts of ideas to try out, and release them to small user populations of about 100,000 or so. It was great because you didn't have to debate much about whether a new feature was a good idea or not, you just built it and tested it. If the feature didn't increase hours watched or retention in a statistically significant way, the feature was removed.
Autoplay massively increased hours watched. I can't remember the exact numbers, but it was by far the biggest increase in the hours watched KPI of any feature we ever tested. There was some skepticism about whether the number was inflated by Netflix continuing to play when the user left the room.
As part of the autoplay test, we tested how long the countdown should be between episodes. 5 seconds, 10 seconds or 15 seconds. 10 seconds caused the biggest increase in hours watched. We thought that it gave people time to digest what they had just watched, but wasn't too fast (5 seconds) where it became jarring. Interestingly, Netflix recently changed the countdown between episodes to 5 seconds. That means they tested it out and found that people watch more if with a shorter countdown. This didn't use to be the case. Netflix user have become conditioned to expect autoplay.
So yes, Netflix wants you to spend more hours watching Netflix and the product team is scientifically engineering the product to make it more addictive.
But...the product team at Doritos does the same thing.