Why do some U8 5v5 games turn into one long counterattack?

It is totally normal for U8s to turn into a basketball game! At this age, the ball is like a magnet and they just want to chase it. Simplify your setup by adding two small gates on the sidelines near the halfway line; if they pass through a gate before scoring, it counts as two. This encourages them to look up and use the width instead of just sprinting toward the goal. Give them one cue: 'find a teammate before you shoot.' Then, let them play! Keep the game moving, keep the intensity high, and let the chaos happen. The shape will come as they learn to trust each other with the ball.