For the streaming factor specifically, I can at least offer something resembling an answer: Google. In the early 2000s they bought up a bunch of dark fiber and peered with all the major US ISPs, and they were able to do this because no ISP wants to be the one that blocks or degrades Google. As a result they were able to host video streaming on their network without immediately being shut down by Comcast and co. Instead they had to go after Netflix.
Google has a lot of custom encoding silicon, too, AFAIK.
Storage is the biggest question of the three. Linus Sebastian specifically called this out when YouTube started really pushing to make the non-Premium experience dreadful. There isn't really some secret special sauce you can buy or make for storage. Literally everything is being stored with the same hard drives, SSDs, discs, or tapes you can just go out and buy. The only specialization you can do is build or buy equipment to handle extreme numbers of them. Google does buy these in bulk, so they probably get a discount on storage, but it's not something that would make storage costs just go away.
Google has a lot of custom encoding silicon, too, AFAIK.
Storage is the biggest question of the three. Linus Sebastian specifically called this out when YouTube started really pushing to make the non-Premium experience dreadful. There isn't really some secret special sauce you can buy or make for storage. Literally everything is being stored with the same hard drives, SSDs, discs, or tapes you can just go out and buy. The only specialization you can do is build or buy equipment to handle extreme numbers of them. Google does buy these in bulk, so they probably get a discount on storage, but it's not something that would make storage costs just go away.