Although the Hangar is one of the least popular properties in GTA Online, there are still valid reasons for owning one.
As far as businesses go, Air-Freight Cargo has been hit hard by powercreep, particularly where aircraft is concerned. This unfortunate setback has hurt the Hangar's popularity, as most players see it as an additional garage instead of a profitable business. However, it isn't all doom and gloom for the old property.
Aircraft still have a niche for some missions, as something like the Buzzard Attack Chopper is still highly useful for grinding out Contact Missions. Naturally, future updates to aircraft can also significantly boost the viability of owning a Hangar, so the player should be prepared for whatever plane could be released in the future. Aside from that, it's the premier property for owning and storing aircraft in GTA Online.
Note: This list is subjective and reflects only the writer's opinions.
Five reasons a Hangar is a must in GTA Online
#5 - Owning a hangar unlocks a new business
If a player is looking for a new way to make money and is bored of grinding other businesses, they could always seek out Air-Freight Cargo as a business.
To participate in these missions, a player has to own a Hangar. It's a decent investment for those who want to grind most of the day in GTA Online.
#4 - Ron Jakowski stops calling the player
Although this reason is a more humorous one than the serious reasons on this list, some players hate hearing Ron's voice.
Even if the Hangar isn't being used for anything useful, peace of mind goes a long way in keeping a player happy in GTA Online.
#3 - Aircraft customization
Hangars possess the ability to customize aircraft, which is particularly useful for weaponized vehicles.
The Hangar is the only place where a player can customize some vehicles, which should be appealing to aspiring pilots in GTA Online.
#2 - Hangars in Fort Zancudo provide safe access
Normally, players are unable to go to Fort Zancudo without alerting law enforcement. Fortunately, there are three Hangars in Fort Zancudo, so a player can buy one of them to gain access to some parts of Fort Zancudo.
This reason alone would likely be the main one for some players, with the next reason being more suited towards players with a lot of money to throw around in GTA Online.
#1 - Hangars are a great place to store aircraft
While this reason may be one of the most obvious ones, it is still unquestionably the best one for owning a Hangar.
Even if most aircraft aren't as powerful or useful as the Thruster or the Oppressor Mk II in PVP, Hangars are still the best place to store them in GTA Online. For example, a player can keep their Buzzard Attack Chopper here.