Tesla Vision Only is heavily dependent on the high quality resolution of the rendered image. This is dependent on hardware improvements which cars do not typical get new hardware, just software. Elon is h3ll bent on dying on this "Vision Only" sword, when all other military and non military applications incorporate radar based enhanced firmware in their object recognition AI. I realize many think Elon was/is a genius, but some are now re-evaluating his thinking on several fronts with his recent acquisitions and radical company decisions. Time will tell as it has with many other "geniuses" who did outstanding in one area and dismal in all others...
IMHO, when the image that Tesla AI is interpreting is significantly distorted by factor(s) of water, fog, low light, lens scratched, etc, the Tesla AI will have to interpret/predict, to the best extent, the poor quality image and make a runtime decision. I suspect, that a Tesla driver will get a warning message something like, "Distance to Objects are impaired. Please use your judgement for accurate distance to objects", which will result in a Tesla driver having to manually use their own vision to estimate the distance to objects. Much like we do in non vision, radar-less, vehicles.
We, FSD Drivers, already see these annoying messages when it is raining, dark, cameras blinded by other car headlights, bright sun, fog, etc...