Cheap fun
There is a certain folk charm in many of the DIY videos I watch. No need to demonstrate mastery of a topic. Just get out there and let your power saw do its thing.
Imagine someone installing a small table. If your screws are the wrong length then you can drive over to the local hardware center and get replacements. If you thing the screw is known as a square hex screw, say so. After all, this is your video, and the rest of the world can decode as necessary. When asked why a table is being replaced, point to your partner, shrug and remind the world that the original one was broken. Not by you, of course.
This applies to more than basic carpentry, electrical repairs are best done with some fireworks. Plumbing upgrades should be wet by definition. Mechanics are always done in next to impossible conditions, because in DIY, a wound is badge for effort. Blood on the ground, where possible.
It might be that the videos sites hide the worst from the public. Very few deaths. Success in a project is relative. Why pay an expert when your middle skills are obviously enough.
I rarely do DIY any more. I understand that working with your eyes closed is for rookies.
Thee watching will continue, because I need cheap laughs. Fun, at twice the price.
Pet videos no longer tickle my funny bone, so I have moved on to new material. And I love watching someone demolish good stuff, as they strive to improve.