It isn't – at the moment.
The output capacity for wireless chargers is measured in Watts. Till today, wireless chargers have only been manufactured to provide up to 15W. A standard 5W wireless charger will take 3-4 hours to charge your phone. In comparison, a 5W wired charge will take around 2.5 hours.
The above stats are for the newer smartphones equipped with fast-charging technology. If you have an older device, it might take even more time. Updating your device when required can also increase its wireless charging capability.
Other factors affecting wireless charging speed are air temperature, the phone's battery level at the time of charging, whether the phone is correctly placed on the charging pad and the age of your device.