Thanks for your well considered and presented post.
I’m not sure I agree because in most pagan theologies the same is true of the mother goddess type - her status is also not necessarily granted by her for her.
Im not sure that Mary’s status is not partially explained in Catholic theology by her own merits.
I do think that distinction is an important one.
While I am a protestant, I will note that some authorities suspect that the Chinese goddess is actually an accretion from early Christianity; and so, in this example, not the reverse.
Christ's Blood washes humanity -- but the pagan Aztecs believed, in essence, that human blood could appease the gods, such as they were. Pagan religions contain innumerable such similarities, often inverted as with Mesoamerican human sacrifice.