We might not agree completely on the widespread use of mail-in ballots, or the expansion of the election from one day into several weeks, but these are matters largely left by the Constitution to individual states. Those issues can be addressed by the states and Congress, if appropriate, at some time in the future.
Many state legislatures, red and blue and purple alike, chose to make mail-in ballots widely available to their voters. State supreme courts, which have the responsibility to interpret state law, have upheld those decisions.
There is no plausible legal basis for federal courts to revisit this decision by state legislators — particularly after the election is over and voters have relied on existing state law when choosing how to vote.
Nor is there any plausible basis to allege fraud in the casting or counting of ballots that could conceivably affect the outcome of the election. Across the country, secretaries of state and citizen volunteers worked tirelessly and conscientiously to count all legal votes fairly. They deserve praise and gratitude, not to be the targets of unsupported attacks on their integrity.