Its interesting you mention Destin from Smarter Every Day, because he always came off as a very earnest learner in his videos. Yeah, he's still putting on a show, but it does seem like he genuinely enjoys and revels in the things that he does. It seems to me like Veritasium has a more contrarian thread of: "Oh, you thought the world worked like that? Well you were wrong, and here's a 15 minute video all about how you were wrong." There's an Onion video making fun of Vox that touches on this perfectly: https://www.youtube.com/watch?v=RpkQEq75y18

I guess to summarize, with Destin it feels like you are learning with him and Veritasium feels like you are being lectured.