What I took away from reading the texas lawsuit is that what you had happen was states were making changes to their election practices due to covid without actually changing the laws. Think how divisive things like voter ID laws are and it's not hard to imagine no election rule changes are going to get passed in a hurry.
Specific examples are pennsylvania allowing absentee ballot 3 days after the election even though by law any ballots arriving by mail after election day are void.
Poll watchers who monitor votes being counted were not given meaningful access to monitor even though by law they must be given access.
Due to the huge number of absentee ballots election counters did not verify ballot signatures as required.
The reason all these lawsuits failed is because there is no real injunctive relief you can seek. And no court is going to nullify an election.
None of these things are evidence of voter fraud but the fact that election officials were allowed to deviate from the legal requirements dictated by law is something I find controversial and is something we should be allowed to talk about.