Pashtun political movements of all stripes (Islamist, Liberal, Socialist, Technocrat) oppose federalism and see it as a conspiracy against them by Tajiks, Uzbeks and Hazaras. They advocate for a strong centralized government and executive branch. Under the current system the president appoints provincial governors and even district officials. Ashraf Ghani, the current president, is a western-educated technocrat who likes to micromanage. He is more educated and less corrupt than Karzai and his family.
As long as the Taliban believe they can prevail militarily then they will not enter genuine negotiations. Some Afghan political figures think that a more hardline military approach will bring them to the negotiating table and accuse secular Pashtuns in the government of stonewalling those efforts and being too conciliatory with the Taliban. Afghan forces have to adhere to "rules of engagement" while the Taliban do not. I would say federalism is preferable.
The government recently reached a
peace deal with Gulbuddin Hekmatyar's Hezb-e-Islami party. He is the most notorious warlord in Afghanistan and received the bulk of American and Pakistani aid during the 80s and early 90s before being abandoned by Pakistan once he failed to capture Kabul and the Taliban emerged. Some see that peace deal as a template for reconciliation with the Taliban but I am skeptical.