This is a revised update from someone who has experienced all aspects that Arma 3 has to offer, including different game-modes, the utilisation of mods, and nearly 5000 hours to boot.
TLDR: Should buy the game, but if you want it for KOTH or AltisLife just buy other games.

Is Arma 3 a game you should buy?
Yes. The answer is a definite yes: nearly 3 years after the game's release and a decade in the testing, the community continue to thrive with around 100,000+ players online daily, new modifications to the game being made, as well as new content on the community hub weekly.
With the game's focus being a military sandbox, it does very goodly on its word as well as the only sort of game in the genre that can offer somewhat of a genuine military simulation as opposed to SQUAD which is more like a quickplay in a military operation. That being said, plenty servers provide this experience too, famously the 77th JSOC co-op servers which puts together 60 players in engaging to control and liberate an area of operation with sub-objectives popping up constantly.

Military aspect aside, it's been turned into so much more with mods: with the king of the hill gamemode it transforms the sandbox into an objective-based first person shooter comparable to the likes of Battlefield, with Exile/Wasteland it turns the game into an apocalyptic wasteland where it has 3 factions pitched against each other in a bloody conflict for resources, money, and control. Altis Life turns the game into a roleplay scenario where similar to GTALife and GMod's Dark RP, you have to create a living. As much as the game's diverse, the community's also divided: some people only buy the game to play AltisLife or KOTH, if you're one of these people, you have to consider seriously why you want to buy a military simulator to play game-modes that the game is not built for, plus you're better off with said alternatives like Battlefield or GTA5 or Gmod.

The common denominator for the community is the groups/clans/milsim: some would argue it's crucial for you to join one of the groups to maximise the play-ability, and I would agree. With groups, you can utilise the most out of mods and all the majesty of a sandbox have to offer. Finding one of the right fit is difficult, and more often than not, some people try way too hard to be tactical and "professional" which can mean a number of things like, "mandatory" training, "mandatory" operations, and things of that nature. It's because of these aspects I've distanced myself from Arma 3 recently and enjoyed some of the new games that's recently released.

This is a revised update from someone who has experienced all aspects that Arma 3 has to offer, including different game-modes, the utilisation of mods, and nearly 5000 hours to boot. TLDR: Should buy the game, but if you want it for KOTH or AltisLife just buy other games. Is Arma 3 a game you should buy? Yes. The answer is a definite yes: nearly 3 years after the game's release and a decade in the testing, the community continue to thrive with around 100,000+ players online daily, new modifications to the game being made, as well as new content on the community hub weekly. With the game's focus being a military sandbox, it does very goodly on its word as well as the only sort of game in the genre that can offer somewhat of a genuine military simulation as opposed to SQUAD which is more like a quickplay in a military operation. That being said, plenty servers provide this experience too, famously the 77th JSOC co-op servers which puts together 60 players in engaging to control and liberate an area of operation with sub-objectives popping up constantly. Military aspect aside, it's been turned into so much more with mods: with the king of the hill gamemode it transforms the sandbox into an objective-based first person shooter comparable to the likes of Battlefield, with Exile/Wasteland it turns the game into an apocalyptic wasteland where it has 3 factions pitched against each other in a bloody conflict for resources, money, and control. Altis Life turns the game into a roleplay scenario where similar to GTALife and GMod's Dark RP, you have to create a living. As much as the game's diverse, the community's also divided: some people only buy the game to play AltisLife or KOTH, if you're one of these people, you have to consider seriously why you want to buy a military simulator to play game-modes that the game is not built for, plus you're better off with said alternatives like Battlefield or GTA5 or Gmod. The common denominator for the community is the groups/clans/milsim: some would argue it's crucial for you to join one of the groups to maximise the play-ability, and I would agree. With groups, you can utilise the most out of mods and all the majesty of a sandbox have to offer. Finding one of the right fit is difficult, and more often than not, some people try [b]way too hard[/b] to be tactical and "professional" which can mean a number of things like, "mandatory" training, "mandatory" operations, and things of that nature. It's because of these aspects I've distanced myself from Arma 3 recently and enjoyed some of the new games that's recently released.