We often earn money from youtube channel by showing ads from adsense and suppose if someone want to earn bitcoin by showing ads on their youtube videos then is there any alternative ad network which provide ads for youtube channel?
Yes, You can.
You just have to cash out all of your ad sense earning directly to an exchange so, you can convert in Bitcoins, And I don't think that YouTube or google will add Bitcoins as payment option if it happens, Bitcoin will rock the world.
In my opinion it is not possible because from YouTube as I know only sharing videos can make you some money and that is also very low. All depends open the viewers. The more viewers on your channel the more money you will earn. But for that you will have to wait for a long time. I think bitcoin forum or investment in bitcoin is the easiest and reliable ways to make money bitcoin. All other sources are not so easy and reliable.
There are lot of video bounties for the ICOs available here in this forum . If you have good number of audience you can make good amount, by making videos for ICO . And you will also get the google adsense .so making bitcoin with youtube is very much possible.
I think it is not so easy because form bitcoin if someone has his own channel and want to earn money he will have to upload videos and he must have to increase the viewers of his channel then he will be able to make some money, but that will take too much time. You can convert your earnings in bitcoin but I think that YouTube is not a good source of making bitcoin. Signature campaign is far better than YouTube.
Signature campaign pays very little compared to how much money you're going to make if you achieve Youtube fame. The problem to some people and the reason why they don't get successful is that they are very short sighted when it comes to achieving goals. Okay, signature campaigns give you weekly earnings. But are you going to do that forever? Is signature campaign feature will always be available in this forum? Or is this campaign will exist forever? I think that like anything else, this forum is doomed to be forgotten at some point.
You refuse to do Youtube because it takes a lot of time, money, and effort. Well, guess what? Pewdiepie didn't achieve his Youtube fame and his daily millions of views with that mentality. He knew that Youtube is a great platform and even if there's a lot of competition, he can do it by just being persistent with the goal. I think you can do that too. I think that you have the intellect to do that. Unfortunately it's obvious that you don't have the willpower to do so.