Standing is the ability of a party to demonstrate that they have legitimate legal grounds to bring their case to court for trial. If a party does not have standing, then the case can be dismissed and won't make it to trial. A judge determines whether or not a case has standing.
In order for a judge to declare that a particular case has standing, there must be sufficient evidence of injury, causation and redressability. Redressability refers to the case having a significant amount of potential to be won by the plaintiff. So, if a judge believes that a case has zero percent chance of being won by a plaintiff, then they may say it has no standing.
Dismissing cases that have no standing helps to prevent wasting the court's time on cases that are not fit for trial.