Is it that his videos are relatively short and digestible in 5 min, and have some off-the-beaten path / uncommon / eye catchy subjects?
Does he just make the right combination of detail and high level takeaway?
Is it that he actually goes to the places to get live footage (versus those Youtube regurgitaters who explain a topic never having left their desk, with 200 ADD-style stock footage clips in a single video)?
Is it that he frames each video with a larger more philosophical question?
Is it because he has a friendly face?
I watch a channel with some quirky British/London guys on weird things about the city (https://www.youtube.com/watch?v=cTLCfl01zuE, https://www.youtube.com/watch?v=Na9iO_HEe14) but it has never taken off like Tom Scott (-- and this is amusing, despite Tom Scott having initially been the guy who designed their intro clip). Maybe it's just too local (no so-what for me) to feel like it's broadly interesting, or they don't lead out to the bigger theme so-what?
Maybe there's just some confluence of x-factors that propel certain people to fame.
Tom absolutely does humour, but its the dry British variety as opposed to the quirky British variety.
Also interesting is that Jay's brother is Beardyman the beat boxer that was a YouTube sensation some years ago with his cooking show!
You'll often do it in regular conversation with people - if you're in a hurry for some reason, you can explain something to someone quicker by leaving out some less important details.
There's also changes in camera angle, cuts to other views, etc.
Tom sticks pretty strongly to an upload schedule, for a start.
His videos also tend to be in the sweet spots for watch time.
His videos all follow a formula, with no start/end padding of note, so viewers tend to remain engaged for the whole duration and not click away or terminate the video early.
His scripts, delivery, fucking clothing choice, everything are all super consistent - which makes his content "familiar" for viewers (even, as one friend said, "comforting"). Tom Scott, the British chap in the red T-shirt, is a pretty solid and recognisable "brand".
Its also worthy of note that his videos entirely dispense with a lot of the "YouTube meta" (soyface thumbnails, YOU WONT BELIEVE..., clickbait, etc), which makes them feel more trustworthy and you never feel like you wasted your time watching some BS.
One of the things I do find interesting though is how Tom has mentioned a few times that production cost on those videos has grown - he has a crew, editing people, video folks, etc. Its no longer just Tom and a camera phone or gopro. However the end viewer sees fuck all difference between early and later videos, barring slightly better camera work (which could be natural learning over time), and better video quality (cameras got better).
Hollywood essentially destroys almost everything it touches: the people that invest in film production insist on maximising their RoI at the cost of petty things like artistic integrity, historical accuracy, and such.
I enjoy independent video producers ("creators" is the term now, I gather?) on YouTube (and Vimeo, etc) like Tom Scott precisely because it isn't Hollywood.
It basically acts as an endorsement of sorts.
Alternatively, start (or stage) a fight with them. A LOT of "YouTube drama" is deliberately staged engagement-bait.
It would be interesting to hear Tom talk about his business, the way e.g. CGP Grey often does on his podcasts.