Certainly there are a lot of people that stretch their videos out to put in more ads, but not everyone with a long video is playing some metrics optimization game. They're just bad at editing.
I think the situation that people run into is something like "how do I install a faucet" and they are getting someone who does it for a living explaining it for the first time. Explaining it for the first time is what makes it tough to make a good video. Then there are other things like "top 10 AskReddit threads that I feel like stealing from this week" and those are too long because they are just trying to get as much ad revenue as possible. The original comment was about howtos specifically, and I think you are likely to run into a lot of one-off channels in those cases.
I think the situation that people run into is something like "how do I install a faucet" and they are getting someone who does it for a living explaining it for the first time. Explaining it for the first time is what makes it tough to make a good video. Then there are other things like "top 10 AskReddit threads that I feel like stealing from this week" and those are too long because they are just trying to get as much ad revenue as possible. The original comment was about howtos specifically, and I think you are likely to run into a lot of one-off channels in those cases.