The corporate jets descended on Riyadh this week, ferrying chief executives to the Future Investment Initiative, a talkfest nicknamed “Davos in the Desert”. A feud between the American and Saudi governments over an oil-production cut by the opec+ cartel, a move which benefits fellow member Russia, was not enough to keep away the bosses of giant American banks like JPMorgan Chase and Goldman Sachs. Nor was the kingdom’s record of…