I wonder why their super computerized battery doesn't just sacrifice some of its 6,831 commodity, 18650 form-factor, Li-ion cells to preserve the others and why

I wonder why their super computerized battery doesn't just sacrifice some of its 6,831 commodity, 18650 form-factor, Li-ion cells to preserve the others and why aren't these cells cheap to replace being the most common form factor of lithium cell in the world.