Evidence is not proof. No one should take as fact something based on some evidence. If there is credible evidence of fraud, there that only means the allegation is credible. If there is sufficient evidence, even that only means some votes should not be counted, whether they are for one candidate, or another.
There is always some fraud. In this case, there will be more evidence of fraud on the part of Democrats simply because Republicans are the only ones looking for fraud. This would be a significant issue for this election if were close, which it is not.