A player with an advanced level of foot dexterity and precision of touch (in terms of weight and direction) developed through advanced juggling practice, will usually have a much better touch in games.
For players who can juggle, the accuracy of their first touch will be better, their ability to move the ball around their feet will be better, and their passing will be more accurate.
Also players with a better 'touch' learn to look at the ball less whilst interacting with it, and so critically this allows them to play with their head up, and so get a better picture of the game.
Playing with the head up (and seeing the game, not the ball) is key to being an advanced player.
But also note, it is not the be all and end all of development when young. If you don't like juggling and don't like practicing juggling then put it on the back burner while you develop in the game functional areas you do enjoy. You will need to be able to juggle eventually, and will need to do the work to master it, but it doesn't have to be the first thing you learn (and shouldn't be if it makes you not enjoy practicing, training and playing).