FireLance
Legend
You know, there are two issues here. One is a steady stream of adventure rewards. The other is the PCs meeting challenges commensurate with their abilities. The two can go together, but they don't have to.It has to do with systems that have a steady stream of advancement rewards that are matched on the other side of a combat equation by challenges, essentially maintaining a virtual balance.
You could have a campaign where the PCs always advance in terms of personal power and magic item power, but face off against a variety of challenges ranging from very easy (a handful of orcs at high levels) to virtually impossible (an army of giants at low levels). You could also have a campaign where the PCs' personal and magic item power is highly variable (due to level drain, curses, long-term injury, destruction and loss of equipment, etc.) but they always face foes that they can defeat (after losing all their magic items, the fights become easier).
Which of the above do you see as the actual problem, or is it only the combination of the two?