There is no way to answer this question. Voter fraud is largely undetectable . All we can do is take proactive measures to stop it. But I would say lack of protective measures will increase the likelihood of fraud.
Well, I do very much agree that absence of evidence is not equivalent to evidence of absence. And I think, when it comes to voter fraud, a whole lot of people have arguments that rest on this false equivalency.
And I also very much agree that nobody has a very good idea how much of it goes on. So, whenever somebody says "There's very little evidence of voter fraud happening often....so why do we need more protective measures?!?" I'm always very unmoved by the argument. There's little evidence of hijackers boarding airplanes very often....but I'm certainly thankful the authorities do their diligence on trying to prevent them from doing so.
That said, if some candidate wants to make a claim that they lost an election they should actually have won -- but for voter fraud -- then I think it's incumbent on them to present evidence that supports the allegation. It's been 4 years since the 2020 election -- and, to date, neither Trump nor any of his surrogates has ever made this case. And yet many of them continue to insist he was the victim of voter fraud.
It's a malicious lie.