Batman yearned to unveil his clandestine identity to Harvey Dent, but his transformation into Two-Face hindered his efforts. Despite facing a formidable adversary, Batman initially sought assistance from Gordon and Dent to combat Gotham's criminal resurgence. His revelation of his identity to Dick Grayson transformed Batman's life, paving the way for the enduring legacy of the Bat Family DC comics.
Robin is one of the most iconic parts of Batman's mythos, but Batman only ever took Robin in because his first choice to share his secret identity with him turned evil.
Batman decides to unveil, revealing Dick Grayson's identity to Robin, marking the second person to ever learn Batman's true identity. While that was initially intended, Batman admits during his inner monologue that the second person he truly desired to share his secret with was Harvey Dent, which became impossible when he transformed into Two-Face.
Batman's first choice for a partner was not Robin. When Batman first started, he was a complete loner, a dark crusader who fought crime without any partners, his only confidant being Alfred. While Batman did work with Gordon, Batman could never reveal his identity to him due to the complications with Gordon being captain of the GCPD at the time. This meant Batman really only had one choice before Dick Grayson showed up, being Harvey Dent.During the early days of Batman's career, without many allies or a large Bat-Family to support him, some of the first allies he turned to were Gordon and Harvey Dent. Together, this trio worked to bring down the mob and arrest Carmine Falcone, who at the time was the untouchable leader of the Gotham Mafia. However, the alliance proved to be short-lived. After a gangster called Maroni threw acid in Harvey's face, he became the villain Two-Face. This new supervillain killed Carmine and betrayed his former friends, which was an especially hard hit for Batman.
After Harvey Dent fell into villainy, he obviously was no longer a suitable candidate to learn Batman's secret identity, even though the villain would eventually learn it later. However, Batman's willingness to keep his secret to himself drastically changed when Dick Grayson entered his life. Recognizing the same trauma he had experienced, Batman recognized that the bond between them would allow him to understand and support Dick's struggles, leading to the birth of Robin, one of the most iconic sidekicks in comic books.