The common mistake
It's tempting to mark most tasks as urgent, especially under pressure. The result is that priority loses its meaning and the team no longer really knows what to do first.
A simple rule to apply
Reserve maximum priority for what genuinely has urgent impact on a client or deadline. Everything else, however important in the medium term, can carry normal priority.
How it helps at the team level
Clear priorities let every team member decide for themselves what's next without constantly asking "what do I do first?", the answer is already visible in the list.
Bottom line
Priority is only useful when it's rare. Use it carefully, so it keeps its meaning exactly when you really need it.