The dirham's peg to the dollar removes an entire category of anxiety for families whose assets and expenditure both sit in the Gulf. It removes nothing at all for families whose children are being educated in the United Kingdom, whose property sits in France and whose income arrives in dollars.
For those families the reported return on the portfolio is close to meaningless. What matters is the return measured in the currency the money will be spent in, and over the past five years that gap has exceeded the entire equity risk premium in several stretches.
Sapna Ventures' practice is to establish a spending currency profile for each family at the outset, updated annually, and to hedge the near-term portion of that liability rather than the portfolio as a whole. Hedging everything is expensive and unnecessary. Hedging nothing means that a family's ability to meet its obligations in three years' time depends on a variable nobody at the table is forecasting.
The instrument matters less than the discipline of having asked the question.