If something is not proven scientifically or with facts it may be considered a conspiracy theory, at least that's the definition of it that I have
Then in that case the idea that masks do anything to stop transmission of the virus is a conspiracy; and in that case the very existence of the so-called novel coronavirus is a conspiracy theory, as the source of the partial RNA sequence which was extracted and labelled as SARS-CoV2 hasn’t been isolated and properly identified as an actual virus according to the scientific gold standard of virus identification.
That’s the problem with the MSM and government covid narrative, the entire thing is a massive conspiracy theory by the very definition you gave of conspiracy theory. I’m not saying there’s no virus, but until it’s isolated and proven to exist, the official narrative is the far bigger conspiracy theory here.