Yes, the giant, carrot-like roots can store moisture for times of drought.
Are there some lime deposits at the surface? The soil looks soggy, dense. Plants look chlorotic. That can come from nutrient imbalance, or inability to process a nutrient because of too high or low PH. Lime in the water can raise PH, especially if bottom watering, or using drip saucers so excess water is unable to flow away.
Also suspect the roots have reached the bottom & started mushing into each other (and more exposed to swings of temp, moisture.) Had spider plants around for about 30 yrs. When they need to be repotted for whatever reason, the foliage can decline quickly.
If you have ground space, I'd put both in the ground for a summer vacation. I think you'll be shocked how great they can look, & so easy to dig up & put back in pot for winter, to go into the hard time of year in the most perky possible condition. If not, repotting would be the next-best thing. Remove all of the old soil, replace with new, a chunky/porous/airy mix that dries quickly.
