Netflix doesn't need to subsidize anything. YouTube subsidizes a lot of videos which don't have ads.
Netflix needs (1) a copy of say Top Gun Maverick (And maybe variations for different resolutions), YouTube needs a bazillion Copies of it with small variations, clips with different music, people "commenting" on it, people actually making commentary, Highlights, YTP's, etc all of it with a wider range of resolutions and also to way more people, plus the overhead of checking against their master copy of copyright infringement
Sandvine is the usual source in the industry and they say: "Sandvine's 2023 Global Internet Phenomena Report Shows 24% Jump in Video Traffic, with Netflix Volume Overtaking YouTube"
https://www.sandvine.com/press-releases/sandvines-2023-globa...