Desk research against primary sources. Figures are traced to the issuing UAE authority and linked on the page.
Mirdif's 5–10 minute range to DXB and Garhoud's 5 minutes both look similar on a map, but Garhoud's calmer residential feel and Mirdif's established villas, schools and Mirdif City Centre mall serve different priorities beyond just the airport run — pick based on which of those two things you actually want day to day.
Festival City's 10 minutes trades some of that residential feel for waterfront retail and good facilities, while Deira being closest comes with busier streets and older stock as the cost of that convenience. None of this matters much if you only fly a handful of times a year — weigh it against the commute to work, which is the journey repeated daily rather than occasionally.