Yes, that’s good point, but at least it is easier to understand in rough conception how the path could lead to it.
Many of the world’s contemplative traditions - Jewish, Christian, neo-Platonic, Sufi and Indian, at least - have held that deep inner examination and gradual detachment from the external world ultimately end up uncovering the “peak” of the soul that lies at the root of conscious experience, and which is, intrinsically or in itself, uninvolved in temporal passage, or the cognition of the changing corporeal things that come into being and pass away, and are inferior and painful. Experiences roughly like this seem to match up somewhat with Plotinus’s “One”, Eckhart’s “Godhead” and Ruysbroeck’s “sparkling stone.” And the description of the jhanas followed by the arupa attainments seems to point toward some state or reality broadly similar.
Since achieving this state involves a stilling, pacification and “emptying” of the mind, rather than a filling up of the mind, which is why it is often described apophatically, it is at least easier to understand how the gradual “letting go” or “release” of mind objects and formations would end up in some such place. On the other hand, understanding how all this letting go and emptying ends up with a person acquiring all sorts of positive powers - being able to fly, to see other worlds and planets, to read minds, to delve into the past, to sink into the earth, etc. - seems much less clear, and even antithetical to the direction in which release leads.
Since the Buddha himself warned people away from the desire to make acquisitions and indulge their will to power, I prefer to think that the attribution of these great powers to the Buddha in the suttas resulted from the imaginings of awestruck and devoted - but confused and unenlightened - followers, who knew the Buddhas was purported to have achieved something great, but could not understand any kind of spiritual greatness different from that attributed to the powerful magi, or siddhas, or divinities, or whatever, of the world’s magical traditions.
So when the Buddha tells stories about the delusions and sensual indulgences and vainglory of Great Brahma or Sakka, for example, I think he was trying to tell people that the nibbana he had attained was a better and more perfect state than even the most highly sought worldly goods, powers and pleasures, maximized to the highest degree as they were imagined to be among the gods. Unfortunately, people sometimes took the wrong lesson and assumed he was saying that he, himself, was actually more powerful than the gods, in the traditional worldly sense.
All the Buddha promises is a path to the end of suffering. If all of this business about the dhamma eye and other super-normal powers is of the slightest importance, why did not the Buddha encapsulate his teaching by saying, “I teach the reality of powerlessness, the causes of powerlessness, the existence of the Super-Powerful, and the path leading to the existence of the Super-Powerful.”