There are many reasons but I think being distracted with petty amusements may be one of the prime causes many fail to reach their full potential.
I came across this enlightened quote from Voltaire whilst reading a preface to his philosophical dictionary, and I wonder how much you think it still applies today, some three hundred years later. I also wonder how much this sad truth may be stunting the development of the “ordinary person” within society to which Voltaire applies the idea.
It is only by enlightened people that this book can be read; the ordinary man is not made for such knowledge; philosophy will never be his lot. Those who say that there are truths which must be hidden from the people need not be alarmed; the people do not read; they work six days of the week, and on the seventh go to the inn. In a word, philosophical works are made only for philosophers, and every honest man must try to be a philosopher, without pluming himself on being one.
The distractions may be different, owing to technological developments, but in my opinion we work at least as much, and there are far more distractions to keep us from reading anything worthwhile or enlightening. Even the news is what we are allowed to see and hear after editing and biasing any story for the particular audience. There is even a protective stratosphere of shallow popular books and reading material in place to keep the readers from anything more serious: biographies, fairy tales (novels with no deep meaning), and cookery books. This is masterful social control by the ruling classes: “What they don’t know won’t hurt them or have them asking embarrassing questions.” However, you are reading this, and so I am preaching to the converted. Reading full-length books is a dying art. You are an artist. Few people manage to read a non-fiction book from cover to cover in the modern era even after purchasing it.