As an old tree is no more able to be bend, Nyom
Cheav Villa , so the older one is, seeing reasons to be bend straight, the harder to do .
There is the story of
The Story of the Son of Mahadhana .
Verse 155
They, who in youth have neither led the life of Purity nor have acquired wealth, waste away in dejection like decrepit herons on a drying pond deplete of fish.
Verse 156
They, who in youth have neither led the Life of Purity nor have acquired wealth, lie helplessly like arrows that have lost momentum, moaning and sighing after the past.
As for the case of becoming nun, there are also age and biological hindrances if one wishes toward Bhikkhuni state (of what is of course not required for path and fruits till Arahat-ship and on.)
As for the benefit and blessing of an ascetic life, the Buddha told that an doubtful King to get ride of doubt:
Samaññaphala Sutta: The Fruits of the Contemplative Life It's just a folk-social usual that people wait till being old. Possible broad fear that to many "worker" would seek for leaving home or lead a modest life at home.