Most people are idiots, so let them - they'll believe any old shite told to them anyway. My mother believes in a lot of this conspiracy nonsense.
I just don't find people making dubious claims on youtube videos "evidence". You you make a claim, you need to back it up, and need to ensure your sources are not complete shit too.
For example, I could say weed cures cancer and I back that claim up with a website that talks about it, but ultimately it would still be dubious as said website likely has not done any scientific testing or collated peer reviewed evidence to back up their claims, and expect people to believe them at face value because they want to appear like they're an "authority" on the matter. This even goes as far as claiming they're a Dr. (likely from a mail order degree mill, inflating an unrelated degree or just made it up on the spot), using scientific terminology, and if they do "tests", are likely easily falsifiable or fabricated to make whatever result agree with their claim. At no point they want things to be peer reviewed, scrutinised or questioned - they want people to blindly believe it purely on authority.
I see this all the time from people who are anti-vax, new age etc - always the same lack of critical thought or any real intelligence. As the saying goes, having an open mind is fine... but not too open that your brain falls out!
