The Taliban are hammering away at the theme of a SOFA agreement being anti-Islam, against Sharia, against Islamic tradition, and unjust towards Afghans.
While many see through their rhetoric, the greater % of the illiterate population that are beholden to their mullahs for accurate, credible information, guidance, and religious legal rulings are affected the by the Taliban's messaging.
All I'm saying is that the Taliban are leveraging religion in a way that is cheap, appealing and effective towards their end state. The GIRoA and ANSF have a tall order in front of them to answer the claims of the Taliban insurgency. The people of southern Afghanistan are very, very religious.