There are only a small handful of voter fraud cases per year: someone tried to vote for a dead relative or whatever. Never enough to change an outcome. https://factually.co/fact-checks/politics/how-many-cases-of-...
On the other hand, potentially far more impactful is election fraud and election interference. Tampering with voting machines (Coffee GA, Tina Peters etc), paying voters (Musk in PA), asking a state to "find more votes" (GA), ...