I understand that you have not had the success that had hoped for, but I can’t agree with your apparent conclusion about are essential basics. Just because you know what the basics are and you can apply them doesn’t guarantee your success.
To use an analogy, If a coach teaching a runner how to run a marathon, gives you the basics, it doesn’t mean that you will win or even place in your first race. You must practice, drill, and build your skills over time before you become competitive enough to win some races.
If you have chosen your keywords well, there will be significant traffic once you have won the rankings “race”. But if you haven’t yet reached a “win, place or show” position, there will be no trophies for you. The basics are the basics and you must master them before you can develop your skillset to reach the level of expert. By your own admission, you are not there yet.
The key to AdSense earnings is abundant, well-targeted traffic. If you aren’t receiving this traffic yet, then you have not yet achieved high enough rankings for the proper keywords. How many #1 positions do you hold? You can’t quit a race before you reach the finish line and expect a trophy, you must earn it. You are in a competition and simply executing the basics will not do, you must excel at the basics, outperforming your competition before you will earn a reward.
In the world of marketing, the trophies are reserved for the winners, you can’t apply Marxist ideology to Free Enterprise, there is no income redistribution, winner takes all.