No doubt the pandemic was also used to remove election security safeguards.
All the earlier cases were dismissed simply because they did not effect enough votes to change the NATIONAL election results.
The courts of those states determine whether the law was violated and the Supreme Court rarely interferes.
The courts of those states have ruled changes in law were allowed. PA Supreme Court precedent included a flood which interfered with voting and resulted in extensions of the voting period. Keeping to the exact days set by the legislature seems less important than requiring citizens to vote in a flood.