Voting by mail should be what is challenged in the SCOTUS.
I checked my local county and yes along with the obligatory vote by mail "more days to vote, more ways to vote" there is still the in-person voting option for those of us who want to do it the right way, on Election Day.
Anecdote: I saw an apartment building where there were brochures of the upcoming presidential primary election, thick brochures with addresses on them, all dumped in the mail junk bin. All of them. Not perused and discarded by the residents but apparently very neatly and all at once by the mail carrier.