Normal mindset
So every time it rains this kind of incident is the norm? … … or not.
'Normal Mindset' is part of the problem. Rain and TX may be normal; follow the SOP, but no reason not to check how far conditions deviate from the Standard, and change Operational Procedure depending on the actual conditions.
Runways are often wet - SOP based on wet performance plus % safety margin, autobrake level 'x', reliance on reported braking action, normal reverse.
But if the 'normal' SOP does not encourage (allow) change, or require a check of the actual runway conditions, calculating the actual landing distance required for both wet and flooded, reassessment and increasing the % distance safety margin, considering the runway surface type and condition for every runway end, crosswind effect, tyre tread on that particular flight, adjusting autobrake setting for each flight, use manual brake, mentally noting the distance still available after slowing down, areas of puddles.
Then without thinking about these issues - a new normal will be established with each overrun; opposed to improving experience on each and every flight.