Do you mean IN the program/video?
Or do you mean that interrupt the program/video?
I watch YouTube a lot but am not a premium member. There are a lot of commercials that interrupt the videos. I expect that as the price of YouTube bringing me the videos that I want to watch. But lately I have also been seeing commercials that are PART of the videos.
YouTube has a feature that allows you to bypass some of the commercials that INTERRUPT the videos. A timer comes on the screen giving you a countdown to the point where you can press the OK button (on Roku remote) to bypass the commercials. Some must be endured for 5 seconds, some for 10 seconds, some for even more, but then you can immediately get back to the program. I guess there are tiers of rates they charge the advertisers: less for the 5 second ones and more for the others. I can just imagine their sales pitch to the clients, "They will be intent on watching YOUR commercial for 10 seconds while waiting for the timer to count down to zero. We can guarantee that 10 seconds for only $DDD,cc." Does that work? Who knows.
Premium members may not see this feature, I don't know. And some commercials do not have that timer. You just have to wait out the full length of the commercial, just like on good, old fashioned commercial broadcast TV.
But the other types of commercials are IN the videos. They are put there by the people, like you and me, who produce the videos. Often they feature the same host as the video itself. Some videos are produced by a commercial company in order to sell their goods or services. The thing here is that YouTube has nothing to do with those commercials. They are sold by the producers of the videos. They are placed in the videos by those video producers. YouTube has nothing to do with them and, in all probability, does not get a single cent from them. StumpyNubs selling a brand of chisels or hammers or other tools is an example of this type of commercial.
YouTube can not eliminate the commercials that are IN THE VIDEOS. They only control the ones that interrupt the videos (often with very crude timing) and the ones that precede and trail the end of the videos. So which type are you seeing?
PS: There are things on YouTube which have none of the YouTube commercials. One YouTube channel that I like watching is Hastings Mystery Theater. They do place some commercials in their videos, but apparently their 1930s and 1940s mystery movies do not draw a large enough audience to attract YouTube advertisers. Many of the shop videos are in the same bucket.