> Vaccine do not prevent spreading,

Vaccines do not entirely prevent spreading. But nothing does.

Vaccines are not entirely useless to prevent spreading. It's one of the few measures that has an effect. Less so with Omicron, to be sure.

Would you say "When wearing a bulletproof vest, you can still be shot in the arm or head, so bulletproof vests do not prevent injury" (and might as well not wear one when in a dangerous situation)

Medicine is not Boolean logic, none of this is binary, all or nothing. We need risk reduction, not sweeping reductive statements.