Stupid question, stupid answer:
Viral dose
You mean "infective dose"
Minimal infective dose - Wikipedia.
And no that is not the question that I asked.
The question is why the physical transfer does not work and the answer is: it does work.
Adding the following:
1. absence of evidence is not evidence of absence
2. the infectious dose has been reported as being vey low
3. we now have a 50-odd percent more infectious variety (and the one in SA which is mooted to be similarly more highly infectious)
... makes my initial statement something to consider.
Now I know I should provide links etc but yeah... people are tired of dealing with .. me too.
You are misreading the reports.
"no reported cases of" and "unlikely to happen (in practice)" means just what they say and do not imply "impossible".
the first is hard to test and the latter is highly influenced by changes in behaviour, the environment and/or changes in the virus itself - all three of which have happened to some extent (fatigue, weather, mutations).
you also need to consider just how many virions a fomite can contain when talking about "infective dose".