The difference is that Bell didn't understand aerodynamics and didn't seem to do a thing about it.
The Wright brothers, not happy with they thought they knew about aerodynamics built their own wind tunnel and proceeded to fully understand what they needed in order to achieve successful controlled flight under power.
Bell's design was nearly optimized for all forms of drag.
Look at the Alaskan panhandle dispute you'd think Canada (British controlled at the time) wanted to give the land to US. Roosevelt threatened to send in Marines to take it by force just because he wanted it. We did not want to give up anything but you get stuck in the middle of back-stabbing politicians and a war monger president you don't have much choice.
I think the huge difference between the Wright brothers and everyone before (and contemporary) to them was that they devoted a non-trivial amount of time to the testing, measurement and understanding of airfoils in their wind tunnel. Before that everyone was guessing. They produced accurate scientific data before deciding how to build their next generation aircraft. Revelations such as wing aspect ratio as a performance factor were crucial. Wing and propeller airfoil selection was also done scientifically.
The Wright brothers, not happy with they thought they knew about aerodynamics built their own wind tunnel and proceeded to fully understand what they needed in order to achieve successful controlled flight under power.
Bell's design was nearly optimized for all forms of drag.