Even in the harsh conditions of surviving on tall cliffs the diversity of plant life may be apparent. In fact, some plants live longer and better here: out of reach of browsers, grazers, tramplers or other mutilators. Aloe comptonii is well set for the contingencies of mountain slope life, as long as people don't impact too heavily.
Pollination and seed dispersal will work just fine. Nutrients are available among the rocks, although sparingly, but growth rate is not a race. Veld fires may devastate large tracts of plant vegetation, but bare rock serves as protection to reclusive cliff dwellers on sites like this (Van Wyk and Smith, 2003; iNaturalist).