At higher levels the game is played faster but the time it takes for boost to respawn stays the same. Once team rotations and positioning is good enough it is wise to attempt a boost steal when rotating back or recovering. Usually when attacking and the opposing team is defending. Taking the enemy's corner boost will starve them of boost, making it easier to keep an attack up.
When defending, focusing on how much boost your Teammates have will help you keep your momentum and make sure that you don't take their boost when they need it more than you. Momentum is the most important factor in keeping a defensive play going. When your defending team is very low on boost, you can force a 50/50 on the ball in your corner. This will slow the pace of the game down, allowing more boost to respawn and let your teammates recover and improve their positioning.