When it comes to rock climbing specifically, there are several climbers who have made significant contributions and achieved remarkable feats. It's challenging to pinpoint a single greatest rock climber, as different climbers excel in different styles and areas of the sport. However, if I were to mention a few names that are often regarded as some of the greatest rock climbers, they would include Alex Honnold, Tommy Caldwell, Lynn Hill, and Adam Ondra. These climbers have pushed the boundaries of what is considered possible in rock climbing, accomplishing groundbreaking ascents and inspiring generations of climbers. Ultimately, the title of the greatest rock climber is subjective and can vary depending on personal preferences and criteria.