Earlier quoted context omitted.
When you can get 10TB [ EDIT: 4TB ] external drives for around $100, this is totally absurd pathway to take towards "preserving your own culture".
It's more like $300+ dollars but there's another, more important point: hard drives fail. If we're talking about YouTube creators who spend hours producing culturally relevant content, we're going to want a much more robust backup strategy than simply throwing it on an external hard drive. Is it possible for a home user to build a storage system with high availability and off-site backups? Sure. Will it be affordable…
I was just thinking about this problem from a different angle.
What if everyone, or at least a bunch of willing souls, ran the following script on their on pc's:
1. YouTube-dlc every video you ever watch automatically in the background and save to NEW_VID directory
2. make a checksum of every file that comes into NEW_VID
3. Check by using the checksum if the file already exists on open platforms like https://joinpeertube.org, https://odysee.com or https://d.tube
4. If not, upload the file.
5. Delete the file.