That was indeed quite the question. Skullius didn't have an immediate response for it because he too had never really questioned it. Perhaps it was because deep down, there were several reasons he considered which erased the whole point of Ashema's question.
The degree of freedom given just by the ridding of costs to the activation of abilities would no doubt lead to the emergence of stronger combatants; the possible removal of limitations in magical treatments and perhaps the evolution of its entire system; greater ambition and achievements in travel and geographical as well as interdimensional discovery; broader definitions of the ceiling of most concepts, and all this was just a macro assessment.
However…