Except that is exactly how cloud companies market themselves. That is exactly what cloud companies have been telling consumers for a decade+.
Right up to the point of commercials showing someone lose a device and saying “no worries, it’s all in the cloud!”, etc. We’ve been told for years that our data is safer in the cloud than it is on our own devices. That the cloud itself IS the backup system.
Normal people didn’t just arrive at this conclusion on their own. They were fed it directly from the companies that we are all now supposed to just innately understand are not to be trusted with our data.
People fuck up, it’s just a matter of when, and when we do it’s better to help and hope that some day you’ll be helped in turn.
And why should they? Google actively markets itself as trustworthy. Unless you know someone who has been burned, the average non-professional YouTube user who just thought it was a sensible way to host their videos would not be aware of the pattern.
I don't mean to be an asshole, but nobody guarantees you that your videos will stay up perpetually on YouTube. Especially if you've got hundreds of private or unlisted videos, it doesn't particularly surprise me that YouTube would pull them down, even if only for petty reasons. If you've been following the state of their website over the past few years, this sort of behavior is becoming quite common, and even among YouTubers with millions of followers I don't think I've seen them reverse a claim of this scale.
Yes, it's a shame. If you don't have them on your own computer though, then are they really yours? It's a hard way to learn that local backups are important, and "the cloud" isn't a panacea for your storage needs.