The phrase "allegedly cannot" is correct and usable in written English.
It can be used when discussing something that is claimed or reported to be impossible or unfeasible, but without definitive proof.
Example: "The company allegedly cannot meet the production deadline due to supply chain issues."
Alternatives: "reportedly unable" or "supposedly cannot".
He gives it a little twitch during its swing through the current, and the fish, allegedly, cannot resist.
And so long as there are prominent liberals who denigrate the intelligence of their fellow citizens and assert solutions that must be applied "for the good of" a public that allegedly cannot govern itself, that problem will remain.
This frustration is often vented at nameless Wall Street analysts who allegedly cannot see past quarterly blips in financial performance to the underlying long-term values these executives sincerely believe they are creating in their organizations.
Thus, it is not merely that we cannot prove whether or not God exists, but the concept of God itself, like all other concepts of supersensible entities and properties, (allegedly) cannot even have meaning for us.
Arbitrary prosecutions allegedly cannot be pursued based 'solely' on 'race, ethnicity or religion,' but they can be based solely on political viewpoints.
And since allegedly you cannot wish for a part without wishing for the whole, any positive mention of the socialist past is seen as ideologically suspect.
The extended magazine Long allegedly used cannot be legally purchased in California under a 2000 law.
Their meagre defence budgets (Uganda's is allegedly $100m this year) cannot possibly sustain their operations in Congo.Once in Congo, the interveners found commercial reasons to stay.
But in a country that cannot, allegedly, afford decent elderly care, realistic university finance, or access to justice, it is extraordinary that the only pre-budget debate is about how to reduce the fairest source of state revenues.
(I say "allegedly" because I cannot be bothered to google it, because I do not care).
With respect to persons whose existence is dependent upon the allegedly harming action, they cannot be worse (or, indeed, better) off owing to this action than they would have been had this action not been carried out.
