I know you’re making a joke, but this really is a (ihmo very interesting) mess:

In this case this is just multiple single points of failure though, at least for the larger ones.

If you lose one of the big red ones in the middle (common carotid arteries) you’ll have a major stroke killing essentially three quarters of one of your hemispheres.

There’s another pair in the spine (vertebral arteries, not visible) which supply the posterior and lower parts of your brain, but they’re also not redundant. Also sometimes, one’s doing basically all of the heavy lifting, and sometimes the other one doesn’t exist at all.

Also this is a simplification and many many variations exist.