I regularly fly 4 different aircraft, only one has a stall warning, the C-172s. I don’t miss it in the others. Besides, an audible alarm is of no use in a critical and stressful situation. At higher stress levels and when concentrated on a task, the brain starts to focus and cut off other stuff. The first thing to cut off is the hearing ability. You may hear things, but the brain don’t react to it, it renders all sounds irrelevant. It is better to learn the behavior of the aircraft at stall, and if you absolutely “need” an indication, a visual one is much better choice, or even better, a physical one (shaking for instance). Incidentally, slight shaking or physical rumbling of some kind is the natural indication of a stall, and that warning is not filtered by the brain even if you are half way into coma. It becomes part of the automated “muscle memory”.
Very true that hearing is disabled in a real emergency, but stall warning is useful for the operating ceiling too, which is where most of mine occurred.
Stall warning on the Rallye is the slats! :)