Chains and tires are something you use over time and replace so they can't be built-in. In this case anyway, because special purpose vehicles do come with deep track tires by default.

On other roads you also want to not have chains or snow tires. You never want to not have AM radio - it doesn't matter if you don't use it and it's basically free given the car cost.

(it's also free as in, the cost of removing it and redesign was likely higher than just shipping it as-is in the next few thousand of cars)