What is your background? I know that many Americans perceive a British accent as snobbish/arrogant (this is often used in Hollywood movies as well). So maybe it's just that?

There are a few youtubers that come to mind who fit this description, but Steve Mould is not one of them.

I feel like your mind must have confused two people. Steve is very down to Earth.

Maybe his youtube-battle with ElectroBOOM turned you off? Where he was pretty convinced he was right about the chain fountain.

Nah I always have the same impression, even though I’ve been watching for years (long before the chain thing), and I can see the janky setups trying to figure things out.

I think it’s mostly the voice / accent, to me it… sounds sneery?

I find him very down to earth with a healthy dose of humour and self deprecation.

Maybe it could be a British thing? Perhaps there's some culture-specific signalling that can be read in a different way in a different culture?

That is what I assume yes, but I don’t know where I picked it up.

I didn't get the impression he's too full of himself, but he was confident for sure. That's not being full of oneself though, that's making a video interesting, confidence, and not filling the space with caveats or self-deprecation.

His voice and presentation style do give me the same feeling. I don’t know why. Same with Mark Rober.

But the actual content is the opposite. It’s really quite strange.

Yeah, I think I can see the link to Mark Rober. Although not at all to the same degree. Maybe it's the way of "acting dumb" in order to progress the discovery process, but a face that they know full well (obviously) that he knows what's going on? Essentially talking down to the audience?

Not sure. My first attempt at phrasing it did not get my feeling across well.

I like Steve Mould and dislike Mark Rober. hmmm. I feel a pretty good judge of character, Steve Mould is quite often humble and self effacing but he does mug and talk in a very intimate way - some people might dislike that from someone they don't really know.

I don't know him but I feel he is a bit tongue-in-cheek with humour. As far as I remember, he did comedy and was also good with education with kids. I don't imagine meeting him and him coming across as full of himself though. I feel I could approach him in a pub and he would have good banter.

some people just don't get there's a joke unless there's a laugh track

This one is pretty representative of what his videos are like. Could be that you got a skewed first impression? Once you watch a few of them, you can see he's pretty genuine.

Full of himself? He literally dresses in a tutu and spins in the mirror in this video.

Too full of himself? I'm not sure I understand, can you give an example?