I very much agree, and if this spring/summer is anything like the last, I'll log 10-15 miles a week with a pack on.. During late May-August it was closer to 40.... But I want to have a good "base" for packing heavy loads and going for long trips on a caloric deficit.
I've not had an issue hiking a long ways with weight, or packing really heavy loads, but I figured trying to get "better" won't hurt.
