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.