If you look at it logically, they are being used as guinea pigs by the government, to see how having a live audience pans out with respect to Covid. Apart from having a fairly typical moan, Ronnie was always going to play in the tournament with the audience, which was only stopped after the first day, due to a government u-turn. As for the £500,000, his wealth is estimated at over £10,000,000 so I don't think that was the main factor. However, winning another world title is what spurs him on.