Fitness isn't everything but it offers a wider range of options in every situation.

About the only place where fitness, if defined as having a low % body fat, would be a negative is cold water survival or near starvation. I suppose that it might contribute to over-confidence as well sometimes.

I spend time sweating my brains out on the stair climber during the week so I can go on 10+ mile hikes on the weekends. (Got turned back by a sudden snowstorm at the 5 mile point on an out-and-back 2 weeks ago. Hoping to do the 12 miler tomorrow in better weather.)