Some plants are naturally short lived......we are talking just trees here....let's not get into annual, biennial, perennial differences.
After a forest fire Mother Nature repairs the damage with quick growing plants......first the forbs (little leafy things) and then shrubs and trees. These first trees are fast growing as they have a job to do, but sacrifice long lift to grow so fast. As a result they also die out quickly but not until the slower growing and longer lived plants have a start under the protective canopy of the nurse plants.
The die out quickly because they lack the ability to ward off disease. I'll explain below. Longer lived trees have the ability to contain disease. Let's leave it at that. This isn't an epistle.
In woody plants.......trees........a plant is under constant assault from fires, insects......and Boy Scouts with hatchets. Each wound in a tree is compartmentalized.......not healed.....but rather isolated by chemical barrier walls within the plant to contain disease development or spread. New wood grows over the wound and we say "healed" but the wound is always there. This comparmentalization takes energy to maintain 24/7/365. The more wounds, the more compartments, the more energy drain on the plant.
Plants "run" on battery power....mostly. That is the plants store energy made by those leaves and then use the energy on a whole host of activities going on even when leaves are absent: new root initiation, flower bud development, leaf bud development, respiration, seed maturation, etc etc and keeping those barrier walls operating. If a plant can not make and store enough energy then systems begin to fail...maybe it won't flower well, maybe growth is limited........maybe the barrier walls begin to fail allowing disease to spread within the plant, destroying more energy with wood cells.
So woody plants basically die of lack of energy.....their batteries are drained and can not recover.