The importance of Outposts

I think that when I play the London opening achieving this with a K on E5 is one of the main advantages/ideas of the strategy.

I think that when I play the London opening achieving this with a K on E5 is one of the main advantages/ideas of the strategy.
do you mean knight on e5? K is king. N is knight. king on e5 is kind of the exact opposite of what you want unless maybe you're entering the endgame or are in some weird position or something.
Ah, but is it the only outpost? Squares g3, g4 anf g6 are also outposts (for black!).
Outposts are extremely important. It's always important to see what will happen if you move a pawn and see what squares will become available. In fact some squares can act like outposts, because the pawn move attacking the square would have consequences. The easiest in the above position is the square h5. Black will take the pawn if white moves g4. So h5 could work like an outpost. Harder to spot might be square d5 for black. White can attack that square only with c4, explosively creating an outpost for black on d3 and a seriously weak pawn on d2.
Strong players will strive to not give away squares. Every pawn move will be considered with the potential loss of control over squares in mind.