There was recently a big 'open chess tourney' (actually https://www.chess.com/article/view/chesscom-global-champions...) to be conducted online. A lot of prize money and you could get to play against the top GMs. I laughed at it because of this very reason -- although touted as 'completely open' as an amateur you would never expect to win, and if by some miracle, like playing the lottery you happened to select all the correct moves, you will still be disqualified as a cheater. There is no point have a prize money tournament where amateur can fight GM (except for the PR) because amateur simply cannot win, but even if God possessed them for one game they would not be able to get away with winning.