Event Listeners & Handlers

element.addEventListener('click', function(e) {
  if (condition) {
    return false; // Trying to prevent default
  }
});

The condition is wrong
return false only works with on-event handlers
Returning false to prevent default behavior only works with on-event handlers (like onclick) and jQuery event handlers. With addEventListener, you must explicitly call event.preventDefault(). This is because addEventListener follows the W3C standard event model, where return values from handlers are ignored. This is a common source of confusion for developers coming from jQuery or older JavaScript practices.
addEventListener is deprecated
The syntax is incorrect