I’ve seen 2 articles on fstoppers on YT ad-revenue:
one said that 1000 views equates to roughly $4.9. The other one said $3. 1M views gets you 3K. So far, he’s approaching the 350K so from ad revenue alone he’s made at least a grand. Plus no doubt from the direct advertising he also makes some on top. Making it >10 mins or multiple of 10 mins apparently increases ad revenue so you can sell more.
For a video posted in November starting off with the v1 firmware times is disappointing. And in fact even after the firmware upgrade, he still mentions 2 hours cool down. Which isn't what I found in my tests with a simple USB fan, especially if you are indoors in controlled conditions. But hey, the full truth doesn't sell YT minutes.
His suggestion of making a grip add on, negates the point as others have mentioned, that for photographers you would be pushing heat to the bottom or the back and not dispersing it efficiently, which Canon couldn't do. Great for video, indoors, on a tripod. Ditto the copper heat sink.
Bottom line - he's talented enough to put together a reasonable solution, which many will want to try for themselves. And he's not as bad as others on YT bending the facts to promote his point (guess that's why he has 2.5m followers). And for his use-case (indoor 8k), sure it will work well enough (assuming an external mic, which isnt near to the fan at the back).
Personally, I think I will wait for the Easter 2021 firmware and see what the Raw light and other modes, and then see where things stand.