I might have been imprecise; in 2000, the claim was that the tallying of votes led to an incorrect result, whereas in 2020 the claim was that a massive number of illegal votes were cast and therefore caused the result to be different than it otherwise would have been. The former could easily be attributable to something like a spreadsheet error (like in TFA), whereas the latter would require malicious intent to commit election fraud. It doesn't seem surprising to me that alleging criminal intent to submit huge numbers of fraudulent ballots in what would have had to be several states would cause a larger public response and interest in the details of how votes are counted than arguing that a single state (Florida) should have to count the ballots again to verify the final total.