Totally agree with you, with the one caveat that Youtube is not operated with long term accessibility in mind. Videos routinely are removed by their creator, or get taken down for silly reasons. And one day Youtube will disappear as well.
Archive the channels you care about - they might otherwise be impossible to find in a few decades, or a few years. Youtube-dl is one of my favorite pieces of software.
Digital artefacts could be, paradoxically, less durable going in the future - if you write and publish a physical book, it might get forgotten in a library somewhere and rediscovered 200 years after you die.
If you publish an ebook on your website and die and no one cares, the probability of anyone discovering it by happenstance 200 years later goes down to 0.