YouTube comment sections are weirdly positive always. It could be a video of some horrible crime and the comments will be about how great the channel is and encouraging the channel to keep making more videos. When j visit actual fan pages anywhere else online there are always a mix of opinions. But youtube is constantly full of obsequious people
Not only can the creator delete comments, but YouTube itself seems to algorithmicly delete comments, especially longer comments.
They also auto delete comments with links, I was doing a tutorial and saw lots of comments asking for help with some issues so I replied to as many as I could.
I reloaded the video later during the day and saw that only some of my comments were visible, I checked the history and saw only some comments were there. Since I had originally written my comments in Notepad++ I saw only the ones with links were removed. You can bypass it by making the link not look like one but it’s annoying if you wish to help people.