[aloha2436]

Easy access to the videos without having to download them from Google (and without Google trying to stop you from scraping them, which they will) is an enormous advantage. There's way, way too much on Youtube for to index and use over the internet, and especially not at full resolution.

[Workaccount2]

That is the other perk, Google has all those videos stored in original quality locally.

It wouldn't be hard for google to poison competitor training just by throttling bandwidth.