In The Path of Sri Ramana (rev. ed. 2023), Sri Sadhu Om offers might seem to be “fighting words” but actually comes out of sense and compassion:

All spiritual practices, other than self-investigation, consider the existence of the individual being or ego rising in the form of ‘I am this body, I am so-and-so’ as real. They are based on the erroneous notion that only by undrrtaking one of those techniques can an individual (jiva), a trifling mental projection, attain its real nature or atman (annihilation of mind or ego). (p. 47, my emphasis)

Why is this passage at once sensible and compassionate?

Let’s suppose that manifestation actually occurred. And let’s say that manifestation unfolds “according to levels.” Then unmanifest consciousness first manifests itself–at least as far as we are concerned here–with the I-thought or I-sense. After the I-thought appears, this metaphysical story goes, then all other sorts of thoughts will appear. The I-thought is thus downstream from pure consciousness and upstream from all objective experiences.

Let’s then admit that the finite mind conceptualizes the world, the body, and others in accordance with the co-arising concepts of space, time, and movement.

Then let’s see that the I-thought is, as Sri Ramana often says, “at the root” of the mind–or, what is the same thing, the multitude of thoughts ordinarily termed the mind.

All spiritual practices other than self-investigation take the “mind level” to be that at which they are operating. Perhaps the mind is to be made more sattvic; perhaps it is to be controlled to a greater extent; perhaps there are to be fewer thoughts; perhaps one is to have certain kinds of mental experiences; perhaps one is to progress through various mental stages; and so forth.

At some point, Sri Ramana would say, you have to “go back the way you came.” Meaning? The I-thought, being the first flush of manifestation of consciousness, is the “chokepoint” or “bottleneck” or “saloon door.” Point being, you can’t not pass through the I-thought in an outward-going fashion (toward objects) or in an inward-facing way (toward consciousness pure).

Therefore, sooner or later you will have to reckon with the question: “Who or what am I, really?” That is, when you stop taking the existence of “the I” for granted, just then you begin to investigate what it is. But that’s self-inquiry!

All other practices, at best, lead to this ultimate question; must lead one here if they are to be worth their salt. And when you resolve this matter concerning who you really are, then all other matters are summarily resolved.