I like being able to compare my times up climbs compared to others that have done the same climb. However, more importantly, I like to be able to quickly look at all of my times up the same climbs so I can see how I am improving. Of course you can do it manually using the lap feature but that is not necessary with Strava. Once a climb is marked one time by anyone on Strava it is there forever, no reason to hit the lap button every time.