It's less "not fightable" and more "no one is seriously trying".

Compare the amount of funding aging research gets with something like Alzheimer's. Which is also a degenerative disease, and worth fighting against - but nowhere near as prevalent.

I don't doubt that it would be incredibly hard to stop aging altogether. But if the effort was there, we might get a way to reduce the severity of aging within a few decades of research. The sheer benefits of being able to reduce the severity of "aging associated" things in a world with aging population would be immense.