Nonsense. There were people who devoted themselves to such arts for decades and never achieved such an art. It has nothing to do with insufficient study or anything along those lines. Teleportation is actively being studied in many scientific communities, and the simple fact is that it requires that you be deconstruction at a molecular level and reconstructed (perfectly) elsewhere. This requires a tremendous amount of energy and is generally impossible for modern technology. To attempt it through sheer will power alone seems inane and pointless. Why? Because it requires infinitely less effort to get up and walk, drive a car, or buy a plane ticket.
Steam technology was available to the ancient greeks. They did not use it because man power was cheaper and more effective. It took two-three thousand years of social, economic, and technological change for it to be practical to utilize the steam engine instead of man and horse power. Concepts such as teleportation in today's world are generally equally fruitless and unnecessary as steam power was to the greeks for very similar reasons.
Those who claim it is just a matter of further study, concentration, and blah blah blah are generally lacking any concept of actual science and simply attribute what they wish to be to "we only need to discover it."
And for those who also claim that anything is possible with enough faith, I also give the analogy of flight. Many people believed that flight was impossible. Many people also believed that they could create flight via machine. How many ridiculous videos exist of people in poorly constructed gliders, hoping, smoking, and girating machines, and other such vehicles that we now know to be completely useless were created? All of those people fully believed that their invention would allow flight. All of those people devoted themselves to study. Their method was flawed however. Their machines didn't work. Wishing, magicking, spells, and ridiculous machines never once made one person fly.Not until the humble hot air balloon, and eventually the airplane. How do we know this? Because it was all sponsored by governments, businesses, and wealthy individuals throughout history. Even Da Vinci had made a glider but it was too heavy to work. Wishing, believing, and hoping for something to be so is not enough to make it work.
Teleportation through willpower is simply groundless and entirely without scientific basis. Every shred of evidence I have scene produced to back it refers to extensive scientific and technological devices or works of fiction.