This is the other thing - Republicans are going to vote for Sliwa because he’s got an R next to his name on the ballot and a bunch of people are going vote for Zohran because there’s a D there. Whatever message exists has a hard time beating partisanship in a large election.
Sliwa's got Staten Island locked down, and Cuomo would need those votes to even get close.
Anecdotal, but as far as I can tell, the reactionary faction in my West Bronx area are also behind Sliwa. They'll never vote for Cuomo, because to them he's just another Dem.
and if they somehow removed Sliwa to put Adams or Cuomo on the R line (which they won't but), you still have the problem that plenty of NYC voters simply won't vote for a republican