I have been thinking about this for at least 15 minutes now and I don’t have a good answer. Here is why. We could look at a couple factors like ability, first ascents, difficulty of climbs and even competition results and I believe that they play a role in making the determination, but at the same time not totally.
What I am getting at is that there are many people who if they had the time (assuming they have the drive) that are capable of climbing routes and boulders at a high level of difficulty. But who is actually the greatest climber? I feel that it could be the climber who has spent the least amount of time training, preparing and climbing. What I mean is that which ever climber that raises the bar in the least amount of time could vie for the name the greatest.
It is not really impressive to me when someone gives a route or boulder 200 times and finally sends it. But what is impressive is the onsight or low attempt send. Any thoughts.