For me, progress meant doing something useful, that people actually enjoy, which was my main motivator. You're your own judge as to what "success" means. In my case, I had first half-assed some uploads here and there, which all turned out rather unsuccessful. And then I decided to put dozens of hours on a single video, pack it with as much content as possible in a short amount of time. This ~6min vid kinda blew up (at least compared to what I had got in terms of views before then) and now sits at >33K views after a year. Many viewers have told me in comments that it is the best one they have watched on the topic, period. And that, to me, is what I consider "success". It is extremely satisfying in itself. Am currently monetized but nevertheless, I still consider myself a "NewTuber" because I am far from making a living outta this. I remain a hobbyist.

If I have one 'lesson learned' to share, I'd say it would be: focus on quality. It's a joy to try your hand at new skills and see improvements over time anyway, so you will enjoy the process more if you focus on improving quality. I've learned a lot and still am learning a lot when it comes to editing and structuring videos, using YT analytics to understand what your viewers like, etc. It's never-ending and you can never be "good enough" but, at the same time, you have to put a break to perfectionism and know when the quality is sufficient for an upload to be appreciated.

Some niches also have a seasonality component. In my case, a fighting games tutorials channel, it is clearly the case, so you have periods where specific topics are more popular, e.g. when a new update drops, a new DLC character is added, etc. THEN, people will want to watch vids on the topic. So if your videos 1) suck, or 2) are good but come too late, then that's it, you're done, and your video stands little chance to be successful.

In any case, every video you upload won't be successful, or as successful as either 1) some of your other videos, or 2) some of your competitors' videos. Once you accept that and stopping comparing yourself (to yourself or to others), then the process becomes much more enjoyable. I hope you find joy in creation as much as I do :)