Moving around large Agile projects, I came across a common situation that hinders the team performance. Individuals cannot allocate time for improving their work (and avoid future problems) because they are constantly firefighting current issues.
It typically happens like this: Someday on the past, the problem has started. Unfortunately, the issue (small at the time) was not clearly identified. It only got enough attention when it was on fire. Therefore the vicious cycle:
Everyone is busy putting out fires -> no time to improve (and avoid future fires) -> more fires
It takes discipline! Finding the balance between fire prevention and firefighting is not easy. You still need the fire sirens. But some experienced firefighters should be out of the fire department before the fire siren alert. Think preventive and proactively!