From my experience so far youtube is like real life, some people will have it easier in some aspects of life, maybe you were born in a rich family and what the lower income population considers a goal in life for you is not but it does not mean your worry's are any less or more important than the person next to you, that being said... some people grow fasters, some have excellent angelic voices that stand out in a crowd and makes you get 1mil subs in a few months, while others "most of us" will struggle our way there and take years to grow but the hard work will be far more rewarding than the ones who get it a lot easier.That is the truth...but I am not here to sugar coat things, this s**t is hard... rly hard... is a god dam grind, but if I can grind 7 years in an mmo with the hopes of being the best at crafting/pvp/myclass ect. then I think I can grind youtube. Give up if you want and let that failure follow you for the rest of your life OR! you can put your big boy/girl panty's and grind this mother*****r to success. You are not special or a unique snowflake so either one grabs this dam bull by the balls or let him horn you. SO DANCE MONKEY DANCE! DANCE UNTIL YO BECOME A STAR.
yes its hard yes we all wanna make it.. be consistent..even if nobody can see the dream you visualising... keep grinding and someday it will all come together..learn from your mistakes take what people have to say about your videos learn from your mistakes and improve every video you make I BELIEVE IN YOU!

I understand about the consistency, but, perhaps the youtubers stop because they no longer find as much enjoyment out of being on youtube or perhaps they have other things in their life going for them and they would rather go onto investing more time on those things that give them a stronger sense of satisfaction. Everyone has the perception that they are doing a lot of work to put out videos or working the most in a workplace environment and perhaps they felt that the cost-benefit of working on other things gave them a larger benefit per cost D:

I dont know im just rambling now. But to sum up, i think if you love it enough, keep going but there are plenty of other things in life to love as well ^^

I just absolutely loved your end note XD