I think the look of your channel does play a significant part in getting more subscriptions. Now a huge part, but a good enough part. To me it lets me know that this person is dedicated, possible professional, and put time into their work. First impressions are everything.
For example, when i was shopping 2 days ago, i was looking at different soups. Of course there is a whole isle of canned whatevers and they all look similar. But i noticed a different one right off the bat, it looked...healthier i guess, different, like it was put together better rather than being funnelled through a tube into a tin can. I ended up buying it lol, they suckered me into the beleif that it was better than the others just by the design of the container.
That to me is what a well designed channel can do for you, a good intro, background, editing can mean a lot. Thats not saying it will get you long lasting subscribers, but it might get you a few right off the bat because you look like your a professional.
just my 2 cents