They could delete the video content and leave a sanitized version of the metadata. For instance leave the post date and title while removing the description and owner information.
Searching for a video's URL might let you find some metadata about it. Unfortunately YouTube encourages social media insulation so a video might have only ever been referenced inside of YouTube with no inbound links from the web.
You can easily imagine situations for which the title itself contains information that someone would rather have deleted. Per GDPR and similar regs, if you want that deleted, it has to be.
It's the uploader's video, and they retain ownership of it. If they want it gone, it'll be gone. Since they own the IP, their interests matter more than some random viewer who happened to add it to a playlist some time in the past.
