>Aiming higher means fewer candidates, and fewer competitors.
Aiming higher also means fewer opportunities, which means competition is tougher, as many people are also trying to move higher. Kind of like a game of music chairs.
The game of musical chairs exists at all levels, but at lower levels one has to leverage network, whereas at higher levels it is possible to leverage competence.
The advice stays the same, everyone should aim high, but rejection letters are not a meaningful signal.
Aiming higher means fewer candidates, and fewer competitors.