JACK DORSEY AND HIS $2.9 MILLION NFT SALE : SUPPOSE BUYER DEFAULTS?

YESTERDAY TWITTER'S FOUNDER JACK DORSEY SOLD HIS NFT FOR $2.9 MILLION. WHAT HAPPENS IF THE BUYER DEFAULTS? IS THERE RECOURSE IN CIVIL COURTS? OR IS THE TRANSACTION LIKE A CHILD'S GAME AND CIVIL COURTS HAVE MORE IMPORTATNT CASES TO ADJUDICATE?