Since one can shoot well with any of a number of different styles, I think that problems are more likely to be in the fundamentals.

Poorly set up gear, either in matching, tuning, or excess bow weight, can keep you from learning the fundamentals. I think it is also a good thing to pick one of the styles mentioned, and there are others, study that video carefuly to make sure you are consistant with that style, for instance elbow position will vary depending on the release and anchor point you use, so trying to keep your elbow in one place but with the wrong anchor would be bad.

The fundamentals are simple:

Strength entirely adequate to the task, practice holding at full draw (and push-ups to compensate for the muscles you aren't working), until you are entirely strong enough. Give yourself time to get there, don't rush.

Think for a moment of your follow through position, then draw and hold your bow firmly at full draw, until the bow is loosed/goes off. You need to repeat this process until you have a perfect release which essentialy fires itself.

When the first two steps are in place, practice shooting at targets. Let the bow fire itself, while you aim. There are many aiming options in barebow. If you want to become an instinctive shooter, probably starting with an awareness of the arrow in relation to the target is a good idea, but you should try to transfer your focus to the target itself, as soon as you can. I prefer not to practice missing, decide on a level of accuracy, don't move back until almost all your arrows are hiting there. Or shoot from one distance like 20 yards for a while until you are good, then work on other distances. Just shooting a lot and missing a lot doesn't teach you how to hit what you want to hit. Lots of variable practice does teach one how to estimate yardage, but if you venture too soon into that aspect, before you can hit a known distance, there is a tendancy to never really get tight on the target.