So as for my actual answer, the way I think about it is kind of a list of an arbitrary number of things, in this case for the purpose of the question, let's say it's 5, although there's probably more, these are the main 5 I can think of right now. And each of these things contribute to success in varying degrees, but the key is that in order to find that success overall you need to do as many of them as you can, as best you can. There's a lot of things, but the few I would consider to be the most important are as follows, in no particular order:
1. Making content that has value. Putting it that way is kind of an understatement but essentially you need to make videos that are worth watching, worth it significantly over all of your competition, even if they have 1000x the audience you do. This can be done in a lot of ways, being funny, entertaining, interesting, unique, etc. Kind of have to figure out how to do that for yourself, but you need to make videos that have some level of value to them. Consider your videos as a 'product' almost, for lack of a better phrase, and then compare your product to that of other successful people. Are you on the same level as them? At the same time, don't confuse this thing with simply making a good video, it's a lot more conceptual than that. You need to be able to explain why someone who has never seen any of your videos should watch one
2. Marketing your videos well on YouTube. This is by far the most important thing, at least simply in terms of getting views. Making good titles and thumbnails is more important than ever, and at the same time is also, unlike making really good videos, a lot easier to learn or be taught. One of the biggest pieces of advice I give to people starting out with no viewers is to spend as much time on your thumbnails and titles and marketing as you do making your actual video. Yeah, maybe it sounds weird but I spend hours and hours on certain thumbails all the time, and it is well worth it. Nobody will be able to see your video if they don't want to click on it to begin with. Personally, I approach it from a very theoretical / conceptual standpoint, of trying to make a thumbnail/title that will make a viewer want to click on the video. Of course it gets a lot more complicated than that, but it's definitely important to learn and understand, past the point of just making something that you think looks nice. At the end of the day, nobody is ever going to click on your video just because it's a great video, it's literally impossible to know how good your video is until after you have clicked on it. The greatest video of all time is going to get less views than the greatest thumbnail of all time, because thumbnails and titles are the only thing people can see and judge before even clicking on something
3. Making good videos at the end of the day is still fairly important. Not nearly as much as most people think it is, but is still necessary for the long term, and is something that can really help you get noticed as an aspiring creator. Do you think your videos are good? Guess what, they aren't. They can always be better
4. On top of that you have a ton of little things, that well eventually sum up to just trying to take each video as it's own piece. Rather than simply trying to get views or eyes on your content, try to make one individual video that has as many things as possible going for it to help it be successful
5. Learn how to learn things about YouTube. Everything and everything I know is simply a culmination of me trying 1000 different things over and over again in different ways and basing information based on results, experiements and statistics.
Anyway at the end of the day the goal is to do as many things as possible that will allow you to accumulate enough potential overall to be successful. And eventually you will land a banger that does enough things right in enough ways that it gets promoted naturally. There has never been a better time to be small on YouTube, the system heavily favors aspiring creators in a lot of ways to allow them to compete. And you don't need to be able to do everything I mentioned, simply enough of those things well enough, and eventually you should find something. But I'd wager most people are a lot worse at all of those things than they think. If you can truly do all 5 of those exceptionally well, you will absolutely be successful, and if you aren't successful, then you are absolutely lacking in some, or many areas. Personally I find that I constantly have incredible room for improvement, and I maybe do 3 of those things somewhat decent, and have significant room for improvement in all 5. Just to give you an idea of how good at them you should aspire to be
Anyway I'm glad I was able to sit down and give you an actual answer, past couple days I was worried I might just put this off until I eventually just decided that it would take too long to answer and not be worth it, but anyway there you go :)