Serving longform is just expensive. A single 20 minute video viewed 100k times end to end can easily cost thousands of dollars in CDN fees. Maybe $2k if using the per-minute streamed deal thorough Cloudflare, easily $4k+ if via AWS and with higher-quality video. So in a future Nostr where videos can get those numbers, earnings from zaps or ads would have to exceed that amount, otherwise the creator is actually taking a loss (or someone else is on their behalf).

Only the creators that can bring a community with them. Not the view-chasing ad-revenue folks.

But serving the same 20 minute video over torrent is cheap (just get a seedbox and put the content there). Also people don't know how to compress things while retaining quality, a 20 minute video could be under 100MB and still be 4k, especially videos where the majority of the content is just a guy talking on camera. Anime episodes compressed properly tend to be 100-200MB @ 1080 (sometimes < 100) and those have a much harder job than compressing a video with a giy talking in front of a camera about the news (or whatever)