Most really esoteric stuff (chakras, siddhis, kundalini, miracles, etc.) at one time was reserved for mystic royalty, the mystic sages and saints of our faith, deep in yogic sampradayas, beholden to the aftereffects of realising Parabrahman, nirvikalpa samadhi, the elite mystic, celibate to the core, all desires no more, karmas gone, no longer aware he even has an ego, able to go where even awareness can't go. Only the most inner of the inner knew much at all, let alone spoke about it.
Somehow (I have no idea how) this once secret knowledge reserved for the realised, passed on to each other through strict Guru-disciple relationships got out.
Instead of remaining experiential, it became intellectual, out of a necessity to interpret it in some way. and the only way available to the more common less sagely man was the intellect. But oh so much gets lost in that process. Rather than an inner dialogue of vibration, just as the sun heats the planet, it turned into words. Are there words for the sun heating the planet, or is it a process that is natural, and words are unecessary. Just go outside and feel it.
So we get scholars standing in temples not feeling it, we get avid but average ego-enhanced folks chatting away as if it were as external as sipping tea or walking a dog.
Fortunately, the true knowledge remains inner, as there are no words for it. The rest is intellectual gibberish, but the mystic understands that as a stage, smiles and shrugs.
In Saivam, there are 4 progressive stages ... charya, kriya, yoga, and jnana. Charya is good works, but disciplined committed good works. It's doing your dharma, humbly, according to the yamas and niyamas, practicing to the best of your ability. It's the basics, the place from where the other 3 start, and absolutely necessary in order for the other 3 to have any success at all.
Kriya is love of God, after the first one is mastered. It's seeing the duality, in order to ultimately realise the monistic non-duality.
Only then do we enter yoga, the quest for realisation, meditating, turning all that kriya within, to see Siva within, to go on the ultimate quest, union with God, that ends in the non-experience of nirvikalpa samadhi, where awareness itself dissolves and is no more, if but for a split second.
And finally we are in jnana, where the inner mystic stuff is. Now we learn to see the chakras, the hundreds of nadis extending out from each body, and if siddhis come they come, but they too are irrelevant.
(A silent sage in the tradition I follow sat still in a tea shop for 7 years, and peoples prayers were answered on small bits of paper, manifesting and floating down in front of devotees eager to learn.) He never once went 'Look at me, look at me, but just sat ... perfectly still)
And so .... I lament, the day after the holiest Saiva night of the year. Will the esoteric knowledge stay with us, of will it disappear, overwhelmed by an intellect so rigid it destroys?