Are you OK with certifying fraudulent elections? Or not allowing complaints to be investigated? I am not.
If election fraud is discovered, and every election has some background noise of fraud, and by some unforeseen revelation in Pennsylvania, Georgia and Arizona 78,332 votes were legally disqualified, then the states would certify new totals. If Trump were to prevail in some argument about irregularities in counting, then a recount might be ordered. It appears that the vote in Georgia is close enough to trigger an automatic recount.
Left only defense is that number of fraudulent votes is not enough to sway the election, but that is not true. If it turns out that Joe Blow voted twice, then election fraud has been discovered, the magnitude of the problem is precisely one vote in however many races he cast a ballot in, Joe is probably in trouble, and no one else really cares much because races with a one vote margin are pretty scarce. But if you’re talking about a hundred thousand fraudulent votes in a statewide race, and there had better be some pretty compelling evidence that this is the scale of the problem, then it’s a different problem. That’s definitely enough to sway the outcome of an election, so there is a high likelihood of the results of the first election being disallowed and a second election being called. I’d also expect some major law enforcement involvement in tracking down and prosecuting the perpetrators.
Article 1 of the Constitution gave states the responsibility of overseeing federal elections. Each state has it's own constitution, and election laws. When state under any excuse, and this time under excuse of "pandemic" unconstitutionally change the voting rules, that is a clear fraud and those elections should be annulled, and new election called.