Why might filling cavities in trees be considered counterproductive?

Filling cavities in trees may be seen as counterproductive primarily because it can lead to additional decay. When a cavity is filled, the material used may not bond well with the wood and can create an environment that traps moisture. This excess moisture can promote fungal growth and further decay in the surrounding wood, undermining the structural integrity of the tree. As the decay process accelerates, it can compromise the tree's health and stability, ultimately making the situation worse rather than improving it.

Additionally, while there are reasons why blocking water flow, increasing tree weight, and cost factors could also be considerations in various contexts, the fundamental issue with filling cavities is its potential to exacerbate existing decay, making this option the most critical to consider. Trees are resilient and can often manage decay themselves if left untreated, but artificial interventions can disrupt natural healing processes.