Or one can learn to aim like most top players do:
DAM
I think most "aiming systems" limit development of one's aiming skills. The brain needs visualization practice and feedback to develop good aiming ability. The only way to do this is to practice the visualization and feedback, and not rely on a artificial (and often inadequate) "aiming system" crutch, IMO.
According to an old article in Biliards Digest, most top players learned via ghostball, contact points, or fractional aiming. And many top players say they don't really know how they aim, they just do it. Regardless, it involves a lot of repetition, a lot of trial and error, before the brain is able to recognize most shots, before the "aim line" becomes something you can consistently pinpoint.
I agree with the whole "crutch" statement. But at the same time, a crutch can be a very effective tool to use in order to assist and speed up any learning/development process. Training wheels are a crutch. A blackjack strategy card is a crutch. The peace sign you use to help visualize a 30° angle is a crutch. The rough method of using your hand and fingers to estimate a shot angle is a crutch. My point is, after one gains a certain amount of experience, these crutch devices tend to fall by the wayside. An experienced player should no longer have to hold a peace sign over the balls in order to visualize where the cb will go. It's just something he or she will be able to visualize. But that awesome crutch or training method helped to develop that visualization skill at a quicker pace than using trial and error feedback. Similar crutch methods can also be used to help with aiming, instead of relying on trial and error feedback.
Knowing the aim line without guessing the aim line leads to pocketing balls more consistently without relying on countless hours of hit and miss attempts first. You give your brain correct information at the start, immediately building shot recognition, without first having to miss a ton of balls before getting to that point where you start recognizing the aim lines.
I think the part of aiming that requires the most learning time is the feedback loop of miss miss miss, make, miss, miss, make, miss, etc... I don't believe it's the fastest way to develop aiming skills. But it is effective, and it works, eventually. However, if you had someone standing there at every shot, pointing, saying "aim here", you would make about every shot (if you have a good and consistent stroke). So instead of shooting 1000 shots using trial and error, missing as many as you make, I believe that shooting just 500 with a known aim line (no trial and error) would be much more effective and quicker at building and paving the synaptic connections needed for aiming skills.
In your DAM method, the first step is visualizing the line of aim. Of course, this is done from a standing position, part of the psr. You say good shooters with good focus who follow the DAM method will make every shot. That's great. But what about not so good shooters? Lack of experience has them stuck at that first step...visualizing the line of aim. Without adequate experience, visualizing the line of aim is not that easy or accurate. It requires a long process of trial and error, missed shots, analyzing feedback, both consciously and subconsciously, until you finally start making more shots than you're missing. And not until then do you finally start paving synaptic pathways related to aiming.
This is where a good "line of aim" system (like Poolology) can speed up aiming development for fractional aimers. You may say it's a crutch, as if that's a bad thing, but crutches are very useful, and they work.