Throughout the time that I have spent practicing guitar/studying theory, it has occurred to me that there are certain skill-sets which are so universal (considered by some to be most-basic) to guitar playing, that no person who desires world-class mastery over the instrument, should overlook them. I am 100% convinced that any-one of sound mind /with no major ailments of the body (ie an amputated arm), can eventually become one of the best in the world at this instrument. (If they desire it strongly enough to reach out and grab mastery for themselves). These are the biggest steps that can be taken towards mastery...
1.) Knowledge of the Fret-board.
I am quite inclined to believe that for the most part, what is slowing down people that want to play the guitar fast is not that they cannot "move their fingers fast enough" but rather, it is a sort of mental processing lag that comes whenever they are playing a piece or passage unrehearsed for the first time, because they have not reached what is called on the adult learning curve as "sub-concious competence" when it comes to what tones correspond to each fret on the board. THESE TONES MUST BECOME SECOND NATURE, do not conceptualize them as only fret-numbers, maintain a constant tonal awareness (ie A#/Bb... ect) of what pitch is produced from a fret every time they are struck. Also, if you at any point are having to perform calculations as to what is the interval between any two frets, it means that you could benefit from learning the fret-board better.
2.) Ear Training
I believe that it is of superlative importance, for one to get one's ear to the point where they can name/feel every interval that the hear (perhaps on one's i-pod or radio) or see on paper (w/o having to spend any seconds calculating) either harmonically or melodically, and with a reasonable degree of certainty. There are certainly many who have gone quite far musically entirely by ear, so it is important to train the ear to recognize all intervals, the sounds of the many qualities/types of chords in ALL inversions (ex. have you integrated into your ear how the sound differences btw/ an Ab 1/2 Diminished 7th with a 6/5 figured bass from a Cb minor triad Add6 in root position?<-there is no particular reason why I chose these two chords as opposed to the infinite others that are possible, but it is important to donate attention to them all) <---this example is meant to show part of the reason why attaining musical mastery is a life-long process.
I shudder to think of how much time I wasted learning while relying exclusively on tablature (though tabs are what this site was designed for) whenever I learned to play a new passage or piece. You can cut this time into a tiny sliver by becoming the best sight-reader that you can possibly be. Don't just rely on published sight-reading books...Sight read ANYTHING that your can get your hands on...(It is necessary to become familiar with all forms of the grand staff ie treble, bass, alto, tenor cleff). Then instead of it taking you several months in the future to completely learn some song that you enjoy listening to, to the point where you could play it while watching a movie and not even thinking about it, it will take you a matter of days. (the time that you invest in developing your sight-reading skills will pay for itself quickly in the future)
Classical guitar virtuoso Andres Segovia said in his book "Diatonic Major and Minor Scales" that those wishing to attain mastery of the guitar should not neglect the patient daily study of scales; they are universal to the Western music system---> learn consistent 3-octave versions of them all (not just Major and Minor, but Dorian, Phrygian, Lydian, Mixolydian, and Locrian as-well & and for All tonal centers) If you desire these things enough, you will put in the effort and time to make them happen.
This list is by no means comprehensive, but if you find yourself desiring mastery of the guitar and stuck in a tab rut, it should give you at least a few ideas to chew on for quite some time.