Maybe of their traffic, but not their infrastructure.
Netflix rents 300,000 CPUs on AWS just for video encoding. Encoding one TV series produces over 1,000 files that sit on S3, ready for those PoPs to pull them in and cache them.
They also do more data processing, analytics and ML than most people realize and that's all happening on AWS.
For example, not only are each user's recommendations personalized, but all of the artwork is personalized too. If you like comedy, the cover art for Good Will Hunting may be a photo of Robin Williams. If you like romance, the cover art for the same movie may be a photo of Matt Damon and Minnie Driver going in for a kiss.
They're also doing predictive analytics on what each person will want to watch tomorrow in particular. Every evening, all those non-AWS servers go ask AWS what video files they should download from S3 to proactively cache the next day of streaming.