You should be looking for ways to better your content rather than places to advertise. Posting in places dedicated for YouTubers to post their videos likely exposes your video to the wrong audience. Generating low community involvement rates.
The people your videos are intended for have no idea that those places [where many YouTubers advertise] even exist, so your audience isn't there.
See the first quote in my signature.
I could have the most amazing content in the world, if no one knows its there no one will view, you have to promote and its not an act of being desperate. All the big companies out there these days, do you think they just had a little shop in the corner of town and waited for people to come....no they advertised they got their name out there. New game on the shelf.....advertise it, Tradesman looking for work, do you think he just sits in the house and waits for people to ring?.... no he advertises his name, puts a portfolio out there to showcase his work.
You damage your own channel by keeping your YouTube private on here, you've obviously been here a while with 1k+ messages, out of all those messages do you not think there would of been at least 1 person that wanted to see what you do? because I guarantee that there would of been but that is for you to decide on what you do not me, If that's how you want to run your channel that's fine but please don't preach to me saying self-promoting is desperate because its far from it, I'll take whatever advice you throw at me but when you just try to degrade people for promoting their content then no please keep that to yourself as it doesn't do anything for peoples spirits.
It's definitely a struggle, especially when everything is so oversaturated and overdone. It's just ask about finding your niche for the time being. Just find digged places you can communicate to the community with and talk around. I'm very verbal, so I try to stand out to people and get them interested in who I am, instead of just my channel. It's all about communication, especially with your viewers (where a mic would help you greatly.) And like the others have said, collaborations are wonderful if you ever need exposure.
Thanks for the advice Fred, really appreciate it, I've got my mic for videos just haven't had time for recording videos with it yet and collabs for that matter, will try and do some in due course.