Swordsmanship is indeed tiring; any physical profession, with the identity of a Warrior, is exhausting to hone.
Although Warriors trained to the extreme have the "physical spearhead" role in a team battle, they can pierce through battle formations, break through Casters' temporary shields, and shatter powerful Demons' scale armor defenses.
Some strong enemies also have defenses specifically designed to counter magic, requiring physical spearheads to handle them.
But on the other hand, despite these performances, overall consideration shows that the magic side also has similar circumstances.
In most cases, using magic to cleanse the battlefield can solve all combat issues.
The so-called counter-magic occurs precisely because magic is effective, leading enemies to deliberately set or evolve mechanisms to counter magic, whereas "physical counter"? One could say all defenses primarily block physical attacks first.
