It is much easier to thread a needle if you have trimmed the end of the thread with scissors, versus trying to thread with a jagged piece of thread.
In order to facilitate maintaining length of hair, you have to trim off ragged/split/damaged ends.
A well cooked piece of meat is much more appetizing if the fat and skin have been trimmed away.
Do you see where I'm going with this? lol
TRIM. Trimming the dead, damaged, useless parts of life makes life easier, better, and more enjoyable.