The true intent of the
The Tathagata declared his supreme goal and that of his followers to be the attainment of the deathless (i.e. Pali: amata, Sanskrit: amrti), alternately described as nirvana (Pali: nibbana, to wit, the extinction = ending of conditioned or caused (therefore inconstant and un-original) formation, specifically of the (s)khandas = dharmas).
The Tathagata equated death (i.e. Pali: mata, later personified as mara = The Evil One) with (everyday) life. *** That’s because (caused) birth ends in, therefore causes death. Everyday life (more specifically, the person formed by the interaction of the (s)khandas, namely of the body, perceptions, feelings, ideation and consciousness) is anatta (i.e. not-atta or anatma = not own = not original or essential) and transitory (Pali: anicca), hence resulting (only) in dukkha, i.e. in unpleasantness, pain, suffering and so on.
The Tathagata proclaimed the supreme goal of the noble (i.e. of the social drop-out become itinerant beggar’s) path to be the extinction of dukkha (dukkha now generally translated as suffering). The extinction of dukkha is achieved:
1. by shutting down the drivers of life, namely lust, ill-will and ignorance; or by blowing out the asavas; or by cutting off the fetters (Pali: klesa); or by developing of the perfections; or by transferring merit; or by doing godd rather than evil (so the coffee table version of the Buddha Dharma, the Dhammapada), and so on
2. by preventing rebirth, i.e. the reactiviation of the drivers of life of which the person (i.e. as actual self-experience) happens as emerged (hence false, so the Gautama Tathagata, but not late Mahayana sepculation) phenomenon.
In short, the (early = hinayana) Tathagata proposed that the supreme goal of the noble life, exemplified by his actions and ruled by his dhamma, is the extinction of the person.
In contrast, a Mahayana Bodhisattva is someone who has decided to postpone the extinction of her or his person (therefore life) and reversion to the deathless (to wit, to the unborn (as identifiable person), the uncreated, nibbana, hence to a state (?) not relativised and expressive of the khandas), in order ‘to free all beings’ from samsara’, i.e. from the cycle of death, rebirth and suffering.
In plain English, it’s the Mahayana Bodhisattva’s job to eliminate all forms of life (read: conditioned formations, i.e. all emerged phenomena) from the universe.
Taking the Bodhisattva vow means dedicating one’s life to helping all life forms terminate themselves (i.e. as false = defiled, because prone to suffering, ‘selves’).
Obviously, the true goal of the (Mahayana) Bodhisattva vow = function are glossed over (i.e. disguised with buzz, indeed fuzz notions, such as attaining ‘universal peace’, ‘the joy of nibbana’, ‘raising spiritual consciousness’ and so on) by Buddhist priests (now mainly Tibetan dharma merchants). Obviously, explaining to ill-informed beginners, mostly Western, that the ultimate goal of their striving is extinction of their personas (i.e. of their actually experienced conscious selves (to wit, the ‘sorry’ bird in the hand) and promising the virtually ‘sure’ - but actually speculative - attainment of the super joyful deathless nirvana, i.e. to wit, the tasty flock of fat wild geese, imagined to exited in a different plane of existence) is not good for business.