For example, imagine I'm restoring a classic 1980s Mini. There's a lot of detail that's only really interesting to people who are actually doing the same task - which is hardly anyone. That's not going to be a highly-rated youtube series.
Whereas a magazine series that shows restored classic cars and provides some details and advice, but keeps things light enough you can half-watch while eating and you won't miss too much? Much more accessible, much bigger audience.
Project Binky goes against this, great series
After all, nobody is following along at home, putting a Toyota Celica engine into their own mini.
When they need to make a wiring harness, or configure an ECU, they're not showing it one cable and one adjustment at a time - that would make for very boring viewing, even if it would be useful as reference material for anyone trying to reproduce their project.
Just like a chess youtuber, very few of Project Binky's viewers are there to study, following along with pencil and paper. Most of their viewers are there to be entertained.
I will admit their videos are substantially more technical than most on Youtube. But because of that, they don't make enough money to go full-time. Actually doing the work constrains them to a video every 1-2 months. In contrast, Hikaru has put out 13 youtube videos in the last 7 days.
Rapid-fire, easily accessible content with broad audience appeal brings in the ad revenue that makes a channel self-supporting.
Slowly produced, niche content for study and reference has to be subsidised by the youtuber having another job.
Learning from online YTubers/Twitch streamers can be a mixed bag. They make the moves seem so easy and logical, without explaining a lot of the why's. Danya is one I love to watch, but he just sees things that players below his level have a hard time envisioning. Rosen is the chillest to watch, but his love of dubious gambits can encourage bad habits as well.