IftiBashir
Undiscovered....
If those channels are doing well it might be due to other factors. I know a couple guys who do well with tech reviews but they show themselves in the video. The videos are still professional but that is just one added aspect to it. Maybe people are more likely to sub when they feel someone is talking to them and not simply narrating a video. Do you appear in any of your more recent videos (the past couple years)? I only watched a couple and didn't see you.
But the short answer, like everyone else has already said, is that you cannot over-produce a video. The more professional the better. I just think that appearing in the video might help the audience identify with you more.
I think this is it - I don't actually appear in any of my videos since Ive always felt the video is about the item being reviewed, not about the presenter. But I understand where you are coming from also, and honestly, I think you are right.
Might have to get over my camera shy-ness and get a green screen set up!
It seems to work as they're my most popular videos!