The sandstone turned quartzite where this Crassula sericea var. sericea plant found its earthly home is hard and durable, not eroding as fast as other sandstone does.
The plant benefits from the rock crack or cracks for anchoring its roots and trapping moisture. Exposed quartzite serves well in capturing the moisture from Richtersveld coastal fogs and dew. Gain for the plant also lies in cooler soil from the white rock reflecting heat of direct sunlight, as shade shrubs are in short supply. The downside of quartzite being low in plant nutrients brings yet another upside: the deficiency keeps competing plants at bay. Almost as when there’s little food in the pantry, fewer family visits ensue.
Plants living here are adapted to concentrate reproductive effort of flowering and fruiting when temperature and moisture are optimal. Their pollinators do the same, hard up maybe from nest building for food from flowers at the time of their appearance. And the small white flowers attracting generalist pollinator insects in sparse terrain have the best chance of maximising reproductive success. Another statistical master stroke of nature in action (Wikipedia; https://www.llifle.com; https://worldofsucculents.com).