before this forum how did the big youtubers gain a following without help???
Keep in mind the time difference. A lot of YTbers back then didn't /need/ forums, they were the main sources of decent quality videos available on YT. It was either stolen content or original stuff of decent caliber. The original stuff was just that, original and unique! People like Smosh and Fred (first two I thought of from back then) felt more approachable and relateable than a stolen flick. When people found those videos back then, it wasn't a hard decision to share! Look at these crazy people doing crazy things, you didn't easily have that ability back then to see those things.
As time went on, it soon became apparent that it was something /anyone/ could do, but by then, the original gang already grew a decent following to be seen as the top dogs. They didn't need to push promotion that much, fans were continuing to do it for them. (And it was made a lot easier thanks to newer sites like FB, Twitter, etc.) Since anyone and everyone can make a channel, now you have a flood of people trying to get big in an almost infinite ocean. Due to the increasing number of options of things available to watch, it's easy for any content to get lost.
For us new people, we can't use the same methods as before, it's a completely different playing field. We /have/ to go different routes and work a lot harder because of how over-saturated the content is nowadays versus what it used to be. Large followings can happen, you just need to be smart, act quick, know your target audience, and have a little bit of luck. (And some patience!) I don't mean to make it sound easy, because for the vast majority of us, it's certainly not!
It can get frustrating, for sure, but if you're passionate about it, and doing what you do makes you happy, then the hard work will be worth it