Hesiod in the 8th Century BC:

"I see no hope for the future of our people if they are dependent on
frivolous youth of today, for certainly all youth are reckless beyond
words... When I was young, we were taught to be discreet and
respectful of elders, but the present youth are exceedingly wise
[disrespectful] and impatient of restraint" (Hesiod, 8th century BC).

Socrates or Plato wrote:

"The children now love luxury. They have bad manners, contempt for
authority, they show disrespect to their elders.... They no longer
rise when elders enter the room. They contradict their parents,
chatter before company, gobble up dainties at the table, cross their
legs, and are tyrants over their teachers."