For me the "keychain" EDC is more about being able to find what you need in the middle of the night without emptying your pockets and losing stuff. It is an organization and accessibility thing. The keychain can also move between different styles of clothing, and components can be added and removed easily. When I travel by air, I remove the items that are prohibited and put them together on another ring in a bag with my other knives. when I am in a suit, I can still carry what I need. The keychain keeps it all together and transfers easily. If I am in the woods and wearing cargo pants, I use the keychain as a supplement to the more robust collection of larger and more durable items I carry then. In this case, it may actually be hung from my belt instead of in a pocket. Everything is done according to personal situation and preference. What works for one may not work for another. What works in one situation may not work in another situation.