Rehne de, tujse na ho payega.
While the hymns of the Vedas emphasize rituals and the Brahmanas serve as a liturgical manual for those Vedic rituals, the spirit of the Upanishads is inherently opposed to ritual.[104] The older Upanishads launch attacks of increasing intensity on the ritual. Anyone who worships a divinity other than the Self is called a domestic animal of the gods in the Brihadaranyaka Upanishad. The Chāndogya Upanishad parodies those who indulge in the acts of sacrifice by comparing them with a procession of dogs chanting Om! Let's eat. Om! Let's drink.[104]
The Kaushitaki Upanishad asserts that "external rituals such as Agnihotram offered in the morning and in the evening, must be replaced with inner Agnihotram, the ritual of introspection", and that "not rituals, but knowledge should be one's pursuit".[105] The Mundaka Upanishad declares how man has been called upon, promised benefits for, scared unto and misled into performing sacrifices, oblations and pious works.[106] Mundaka thereafter asserts this is foolish and frail, by those who encourage it and those who follow it, because it makes no difference to man's current life and after-life, it is like blind men leading the blind, it is a mark of conceit and vain knowledge, ignorant inertia like that of children, a futile useless practice.[106][107] The Maitri Upanishad states,[108]
The performance of all the sacrifices, described in the Maitrayana-Brahmana, is to lead up in the end to a knowledge of Brahman, to prepare a man for meditation. Therefore, let such man, after he has laid those fires,[109] meditate on the Self, to become complete and perfect.
— Maitri Upanishad[110][111]
do believe Buddha was a figurehead for the reformation, and obviously he/they wasn't/weren't alone in pushing against social control. True revolutions are slow movements.
...and you edited your post without updating me. Well, that's what I said Buddha didn't started, Buddha was a branch of that revolution. When vedic Hinduism transformed itself into classical Hinduism during axial era.