I agree with most of your points. I think life is much more arbitrary than we think. Our minds try to find causality in most of the things that happen to us. "I did X, therefore Y happened. If you do this, you will get that."
It is not so straightforward as people think. There is lots of randomness in life and success can be pure luck. We always look at the successful people and try to find patterns in their behaviours so that we can copy and be successful as well. This is hindsight. But noone can look at a person today and guarantee that he will be a big success in 5 years. I watched one of the first videos of PewDiePie today. He was no different than most of today's average YouTubers. But he made it to the top. Is he good? Yes. Did he deserve it? Yes. But it could as well have been that some other gamer would be the hype and not him. Who can tell? All the people copying him today are not nearly successful.
I believe that a small YouTube channel is like a start-up. There is a high probability that it will not become a big success. All YouTubers should know this fact. The competition is high and success formula is not very clear. A YouTube channel is a very good training ground on entrepreneurship. You can see it as a business and people surfing the web are potential customers. Your videos are your products. You can have occasional customers who view your videos and loyal customers who are your subs. You are charging each customer around 0.001 $ per view. Your goal is to increase the number of customers and have more loyal ones. A YouTube channel as an entrepreneurship training is extremely valuable. It is not costing you much except your time and the downside is nearly zero. What if you fail? You start another channel or pursue another hobby. What's the big deal?
The success of a start-up is as well mostly random. Why did Facebook become popular? There were lots of other friendship sites at the time. Why did AirBnB become a big business but not Couchsurfing? How come Google beat the giants Yahoo and Microsoft in the search business? Why was the Gangnam style so popular and not some other horrible music? People can find reasons in retrospect, but it doesn't mean that the reasons were the real success drivers. We can't prove it with an experiment. Maybe it was totally by chance.
Back to success on YouTube. Yes, there are some patterns, tips and tricks. These are already mentioned several times in this forum. If you work hard and follow these recommendations, you will get a decent number of viewers and subs. But it won't guarantee that your videos will be viral and you'll be the next PewDiePie. But the more you try, the higher your chances are. I think it is worth a try to get several tickets for this lottery.
Regarding the rich get richer. Yes, it is true in YouTube as well as in real life. The rich on YouTube are the creators with trusted content and YouTube plays it safe not to lose the viewers. They make money out of that, YouTube is not a non-profit organization. YouTube also needs the small channels to keep its community and offer interesting, original content. The small channels made YouTube what it is today. So, it gives us some chances but not much. You will not be ranked #1 immediately despite several SEO tactics.
Whether we like it or not, these are the rules of the game. We either play it accordingly or sit at the bench. A friend of mine hated girls, because he wasn't successful in his attempts to date them. He said: "Girls prefer a**holes to nice guys". I suggested him to stop being a nice guy then. If this is the game, learn the rules. At least pretend.
I see lots of energy and enthusiasm on this forum. There are people who are creating content instead if just consuming it. People who want to learn, improve and share. This is a great community. All of us are buying the tickets and hopefully some of us will win the jackpot. Good luck!