I download all of the videos like this so that in 30 years when free speech is illegal and you have to scan your id embedded in your brain chip to access the internet i can show them to the future generation before my brain gets fried for wrong think.
Archive.org may be soon loosing a copyright lawsuit that will put them out of business. Better not rely on one third party for something this important.
Still need to be careful. I once needed redundancy for simple web service for a hobby project. Set up 3 free websites on different hosting providers. Turns out all 3 were owned by the same company, running on the same servers so my service went down anyway.
you could probably figure it out with a bit of google fu. Though you would also still be dependent on potentially 3rd party factors at that point. Like using cloudflare for example. They've been known to break the global internet a few times.