2.8 has exhaust hot spot. Valve order (I for intake, E for exhaust) I-E-E-I-I-E. So, 2 exhaust valves, side by each. The hot spot limited the power the engine could develop.Do you want to own a 2.8, how is the 2.8 weaker than the 2.9, what would be the difference between a carburated and fuel injected ranger.
The 4.3 V-6 gets better fuel economy and makes its power at lower rpms which is more usable. Who wants to be reving to 5k rpms all the time. That is basically @rusty ol ranger 's complaint - 2.9 makes power at lower rpms which is where most people drive, so better driveability.
And Chevrolet has tons of aftermarket performance parts at relatively low cost; you could build a 4.3 with 50% more power than Ford for less money. But yes, the S10s were cheap.