you do not “replace data until your desired objective”.
the original model stays intact (the W in the picture you embedded).
Meaning that when you change or remove the LoRA (A and B), the same types of biases will just resurface from the original model (W). Hence “less biased” W being the preferable solution, where possible.
Don’t get me wrong, LoRAs seem quite interesting, they just don’t seem like a good general approach to fighting model bias.