Biden is President elect, and Trump knows it.
Everything else is theater. This is Trump's last con: to convince the brainless oafs who support him that there was massive election fraud. Trump's self image and ability to sell himself to Deplorables, to sell real estate, to sell frozen steaks, is predicated on the perception that he is not a huge loser.
Deplorables have been trained Pavlovian-style to believe Trump is not a loser and that he will always "stick it" to the libs.
And that is why all this kabuki theater is the last con of the biggest loser, Donald Trumpf.