The PLO (also called the PA) has consistently been brought to the table, and rather than wanting destruction of the PLO, Hamas, the PFLP, etc all maintain their stance is to reform and democratize the PA as a national unity group. Strides have been made in that direction thanks to events like the 2024 Beijing conference, where all of the Palestinian resistance groups and the PA were brought together. The PA is also the internationally recognized state authority over Palestine. The idea that the PA doesn't at all count is, so far, conjecture on your part, unless you can find a primary source indicating that it isn't.
I disagree with the PA's decision, and I know they are compradors. However, the resistance doesn't claim to be the authorities over Palestine, they maintain that the PA is, and that the PA needs to be reformed. Until that happens, the PA will always be seen as legitimate for the sake of UN resolutions.