In season 4 they reduced the XP and Gold earned from waves and buffed this for Jungle camps. This means that when Guardians and/or rest of the team falls behind in Conquest, they will get less gold and experience than they used before. This is specially applied to Guardians as you will realise you are underleveld and underperforming no matter what you do, unless you are a fed guardian and your team have good jungle controll. If you find yourself in a position were you and your team cant farm from the jungle due to the enemy having better controll or are leading in other ways, you will eventually lose the game. Now you have to share waves with your teammates trying to defend towers and phoenixes as the enmey team get more and more money and levels due to their controll. This happens often due to the team with best early game usually start clearing the jungle withouth the other team being able to contest, because they will be 1 or two levels behind.