Friendlies do not matter. Actually, let me re-phrase. The results of friendlies do not matter. What happens in them does matter, but whether you win or lose the game has no bearing on the future of the team.
The point of friendlies is primarily two-fold: to provide players with a chance to gain match fitness and sharpness, especially if they are in pre-season; to experiment with systems, personnel and tactics, better installing the approach of the team and understanding which players have the abilities and skill sets to execute such an approach.
For international friendlies, because players are usually sharp when they arrive in camp, it is this latter point that is especially significant.