If Trump had won a second term and acted as you claim (big if), then his peace deal would have turned into yet another indefinite military commitment. Because “Afghanistan control of each province” was a chimera.
The speed at which Afghanistan forces melted away shows that they could not have been sustained by any amount of additional “preparation.” They needed, apparently, an indefinite commitment of professional American troops and manpower behind them. All that to only control about half the country and be on a perpetual civil war footing.
20 years to prepare for the inevitable U.S. withdrawal, and half of Afghanistan collapsed in a week. Is that surprising? Yeah, it kinda is. But even the most optimistic predictions didn’t have the government lasting more than 18 months.