I’m of the opinion that they both have the same mileage on them and the same real wear and tear so if replacing one, I personally would replace both.

I know it’s a bit of a pain, but with the belt being driven by the crank pulley that belt is turning constantly even with the ac off - granted with very little/no load, but still subject to all the same heat cycles, etc under the hood.

My thought, change them both [emoji106]

No REAL need to, to your point, car will still run, unless that belt shreds and takes the serpentine belt out with it... just sayin...