I think he is as genuinely as smart as he is claimed to be. However I don't think that's any more likely to make him correct about his theories, especially at this young age. Calling him wrong is not the same thing as calling him fake. I doubt he's been alive long enough to have assimilated enough of the existant information to make plausible new theories. His best work is probably 10-15 years in the future, at which time he will probably look back on these youtube videos as evidence of his youthful enthusiasm untempered by wisdom.
Isaac Newton once said, "If I have seen further it is by standing on the shoulders of giants". Barnett is too young to have climbed up on the giants' shoulders or even to have realized yet that he needs to. But eventually (most likely in his 20's) he will. And then he will see further.