The sutra reports that Dharmakara completed his vows and became the buddha Amitabha, boundless light, presiding since over Sukhavati, the pure land in the west, and every claim Pure Land Buddhism makes about calling on Amitabha's name rests on the premise that this transformation genuinely occurred, that the vows are kept rather than aspirational.
Chinese, Japanese, Korean and Vietnamese Pure Land traditions read Dharmakara's story less as a myth about a distant founder than as the legal basis, in effect, for the practice they teach: because the eighteenth vow was fulfilled, a sincere recitation of Amitabha's name today draws on a promise already honored, not one still pending.
The thirteenth century Japanese teacher Shinran pushed the logic further, arguing that even the trust needed to recite the name sincerely is itself a gift arriving from Amitabha's vow rather than an achievement of the practitioner's own effort, since Dharmakara's labor was undertaken precisely for beings unable to save themselves. Dharmakara himself effectively disappears from view once the transformation is complete, remembered afterward almost entirely through the identity and the vows he became, rather than as a continuing character in his own right the way a bodhisattva still active in the world might be.