There are studies on the persistence of the SARS-CoV-2 virus on surfaces. These studies aim to find out how long a surface remains infectious to humans.
As far as I understand, it is not determined experimentally how long a surface remains infectious, or whether significant numbers of the viruses are present. Also, these tests do not identify the complete RNA of the virus, instead detecting the presence of fragments of viral RNA.
Now, some theorize that viruses in a droplet become inactive when the droplet evaporates. I think the expected effect depends only on the virus being dry, but maybe also the process of drying and the liquid.
That can't be right, because it would mean that a surface a person has sneezed on would be harmless after only a few minutes, and that's wrong.
We think surfaces are infectious for practical purposes. But is that established experimentally? Or do we only detect RNA fragments, and use this to infer the presence of viruses?
If so, this may imply infections attributed to touching dry surfaces are in fact caused by direct human interaction, or by touching wet surfaces. That problem could be undetected because the time between surface contact and symptoms is so long. Also, studies regarding the virus did not have much time until now.
Is it possible that droplet evaporation destroys SARS-CoV-2? Is it probable for practical purposes?