Unbelievable. I do not really know how to reply politely.
I will repeat: go and hunt the wealth that it does contain. It is not a sign of mental development to pick one piece of trash and say that it exhausts the content. See https://news.ycombinator.com/item?id=50140206
It's not that bad. Hard drives are still about $30 a TB, long-form videos worth preserving are around a GB each in decent quality, so they cost about $0.03 each to preserve in decent quality. It's not free but it's not too expensive either. $0.06 for redundancy, $0.04 if you use erasure coding (e.g. RAID-6).
Reduce that by a factor of 10 if you accept noticeable visual artifacting while still conveying the information - that is, if you believe it's not necessary to preserve every pixel as long as the information content remains. If you're focused on quantity of preservation over quality, you should do this.
Again, you do not seem to be appreciating the context. You are suggesting that cultural preservation and accessibility, that should be a goal of States (good luck nowadays about their goals), and is today in one of its most important cone (video material) in the hands of an enterprise, should be replicated (in its important subsets) by private citizens.
You are forgetting, past scale, legal details (the MIT and Stanford etc., and even the holders of old material, chose to publish their content on YT) and systemic details (Lesics and Asianometry and Alpha Phoenix and Sabine Hossenfelder and Steve Mould and 3blue1brown and Thoisoi and the very many others who are producing content specifically for the platform can do it financially because of visiting users on YT - not on backups), and the absurdity.
I will repeat: go and hunt the wealth that it does contain. It is not a sign of mental development to pick one piece of trash and say that it exhausts the content. See https://news.ycombinator.com/item?id=50140206