I don't think it's just coping, but it depends on the level of mastery you want to achieve in the specific discipline. For any skill, including weightlifting, the more you practice, the better the quality of the skill. And becoming competent at something is one of the pleasures of life.
For the amateur athlete, one has to take into account the opportunity cost of doing something else, and life is full of opportunities.
As for grit, I agree it is more about showing a personality trait than developing it, and grit appears to be mostly discipline-specific: many athletes show admirable grit when training and less than admirable grit in other areas of their lives.
That’s fine if you want it to be a hobby. Admirable even. But not everyone wants yet another hobby. If you could get the benefits then the vast majority of folks I don’t think would miss anything meaningful. You’ve got to enjoy the tertiary benefits to stay sane, but I’m not kidding myself that I wouldn’t enjoy ~5 hrs/week back to pursue other activities.
