If you shoot around 95 you will see improvement in 5-shot jumps if you practice diligently and take a few lessons. Equally, a player who scores say 87 will quickly come down to 81/80. The next downward plunge would be to the middle 70's. Once you play 75 regularly you are not an average golfer but will be seen as pretty good.
Improvement down from the mid 70's comes more slowly -- probably because the psychological aspect of the game comes to the fore. Cure a slice and automatically an 87 becomes an 81. However, leaving this plateau becomes harder and harder to move away from if you wish for better scores.
Attention to detail becomes distinctly relevant when trying to reach 'expert golfer' status. More distance, straighter shots, precise chipping, steady putting, good bunker play and reaching more greens in regulation is easier said than done.
Golf's general rule of thumb is that the 75 golfer can become a 72-shooter only if their short games are exceptional --unless their short game made them play 75's in the first place. The short game is where you can turn 3-shots into 2, and the higher your score the faster you can reduce it. There's no mystery here as every knowledgeable golfer knows that about half of their shots are struck within 60-yards of the hole.
Out of Bounds: Miserable golfers are not happy with themselves, so they project their sad unhappiness and useless shots onto others.