Maybe it is not about the costs involved. Perhaps they just enjoy making things. If they make a video and get ad revenue then good for them. Nobody is forced to watch anything and can easily switch off the video if not interested in the content. I went to quite a bit of effort to produce this.......a plastic one could have been bought for a fiver. I never did it because I couldn't get one or to save the fiver, I did it because I wanted too.
I'm not sure why people take this personally. Your circumstances (I make all kinds of things that make no economic sense) are far away from someone making a well produced and edited youtube video with good sound and good light. It takes probably as much time to edit the video as it takes to make the item. It's not like you making something you enjoy, or me spending 85 hours to make an infill plane that costs about as much for materials as a used Spiers.
The reality is youtube is formulaic. It takes a lot of work to fit into the formula and when you see someone with several hundred thousand to millions of views on more than one video, it took them a lot of intentional work meeting the youtube formula to get there. I can tell you from experience that if you just turn on the camera and turn it off, and turn it on, and off, etc. without very intentional camera work and editing you'll get a couple of thousand views and there will be zero chance more than one of your videos will go viral (and if you get a viral video, it would probably be a 15 second clip of a pet doing something funny while all of your tool-related videos get almost nothing
What that means is that almost anything you see like this video has little to do with just making stuff for fun - the guys who rise to the top are the ones intentionally following the youtube model. Success is fleeting, too- eventually, youtube will take even the most popular content makers and start using their videos to introduce viewers to other newer youtubers.
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..well, there is one other type. The rick beato or matthias wandel type - both of those guys do or did originally use youtube to link viewers to an external site where they sold something. Wandel sold plans and beato sells some kind of music software or instruction off of youtube.
The idea that a guy likes to make 12 pound dust collector parts and is willing to spend a full day editing, and then will do that more than a couple of times for the love of sharing things they make is unrealistic. They'd just make those things and not constantly stop and change lighting, etc.
There *are* some superb end to end video sets like Curtis Buchanan's video on how to make a chair, but he more or less condensed a lifetime of work into a series of videos - and even at that, his videos have far fewer views than the "golly-ghee i could get something for nothing" type crap that youtube promotes (like newspaper logs, etc).