Lots of manufacturers offer the double-pole option simply because it is very easy to make the pole sleeve large enough to take 2 poles. Frankly, I think that's why you see it mentioned so often. I question how many have ever implemented the idea for real.
But do they help? Well, that depends on the conditions. This tent:
has single 7.5 mm carbon fibre poles and silnylon fabric. It took winds well over 100 kph from the rear end on a saddle one night - for further details see "When Things Go Wrong". (Stupid place to be camped ...) It showed no sign of stress with the wind end-on. My wife watched the tent behaviour for a bit, and then went to sleep.
If you had this tent side-on to the wind it would be a bit more loaded, for sure, but the closely-spaced tent poles with the double guy ropes were able to take some pretty bad weather on another night. The photo does show the wind side-on - it was taken the day before the peak.
The killer is the wind gusting straight down, as I have mentioned. Yes, the extra strength of double poles would of course help here, but you would be better advised imho to use internal guy ropes across the tent to stop the poles from buckling. The weight of the internal guys is negligible, and their contribution is actually significantly larger than that from double poles. Yeah - you have to dodge the guys when you sit up, but we are talking some pretty savage conditions here, and under those conditions you LIKE seeing the extra strength! Caveat: the tent must be designed to use internal guy ropes: most are not.