Pressing is a decision, not a distance
The thing I keep seeing at every level, from under-14s to senior football, is a team pressing hard and pressing alone. One player sprints at the ball, the two behind him hold their line, and a gap opens up exactly where the opponent wanted to play. That is not a fitness problem. Nobody was unfit. It is a decision problem, and decisions are coachable.
A press is a group agreement about when to go. The trigger has to be something every player can see at the same moment: a bad first touch, a pass into feet with the receiver facing his own goal, a back pass, the ball travelling to a weak side. If the trigger is visible to one player only, you get a chase. If it is visible to the unit, you get a press.
What I work on is the second cue rather than the first. The front player has an easy job, he follows the ball. The player behind him has the hard one, because he has to leave someone to take a space, and he will get blamed when it goes wrong. Until that second player trusts the agreement, a team will keep looking passive while running further than the opposition.