The commonality of methods arises from the fact that people are the same everywhere, endowed with the same senses and the same reflexes. The states of mind and priorities are also similar, adjusted for a specific culture, and the number of principles in a person (spirit-soul-body) is also the same.
If we explain using the example of martial arts, then an elbow strike, it is an elbow strike in Africa as well, and if you put an African and an Eskimo near the same trees and give them the same axes, then they will chop almost the same way.
It is such a regularity that leads to the fact that the most optimal solutions are selected, which are preserved and transmitted in tradition. In India, these methods are known as yoga. This is, of course, about traditional yoga, and not about the one that is practiced today in fitness centers.
Yoga, as Patanjali defined it, is citta-vritti-nirodha (Skt. Cessation or not generation of states of consciousness). Notice how consonant the word "nirodha" is with the phrase "not to give birth." Consequently, the change of states ceases, since the mind has ceased to be dichotomous (dual).
This state was labeled as vairagya (liberation). Consciousness ceased to perceive the world as a disparate whole and realized the unity of all Being as a direct experience. These experiences accumulated and over time created Bodhicitta (illumined consciousness). Here, if you like, is the brief goal of yoga, like any other system, be it Buddhist or Egyptian.
Patanjali's methods of attaining non-duality are clearly and understandable, but only purely theoretically. It never occurred to anyone to practice yoga on their own. The guru was the first and foremost condition, and all the specifics flowed from him. Sutras, like other books and treatises, are nothing more than a synopsis and "reminder".
The practice began with ethics and the fulfillment of the precepts, and only then one should hope for success in dhyana (contemplation). Everything proceeded from the same conditions. Only the object for concentration changed, and the methods of calming the surface mind were almost identical in all traditions: to calm the mind, distract it from external stimuli, suppress mental dialogue, focus on the object of contemplation, and liberate consciousness. It is clear that in most traditions the results were very much the same.
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All these developed methods required compliance with certain conditions, which included an ascetic life and being in solitude, that is, everything that is practically inaccessible to a person in society.
A city man should give up the unrealizable dreams of becoming a yogi, sitting on the couch, and make efforts for even a small but advancement. Such steps must be applied daily and do not lose heart from possible failures.
Andrey Vl