What is a disadvantage of allowing faster groups to play through?

Allowing faster groups to play through can create a situation where the original slow group becomes left behind, effectively relocating the bottleneck instead of resolving it. This occurs because the faster group, having been allowed to advance, may remove their own delay but then create a new delay by continuing to play at a faster pace that further disrupts the flow of play for others behind them. This can lead to frustration for the slow group, as well as for those playing behind the newly formed bottleneck.

The other options do not accurately reflect the challenges posed by such a scenario. Finishing all players at the same time implies synchronization of pace that is often disrupted when allowing faster groups to play through. Claiming there is no impact on course flow contradicts the very nature of what is happening. Furthermore, the notion that fast groups tend to slow down does not inherently relate to the concept of playing through; while it might occur in some scenarios, it does not address the core issue of relocating the slow play bottleneck.