When I graduated with my degree in electronics, I found the software industry paid much more than the electronics industry, so I entered the software industry.
If the electronics industry wants to hire me, they would have to pay higher salaries. So the salaries in one industry (software) can drive up salaries in another (electronics)
Admittedly, nobody's leaving programming to become a miner - but plenty of jobs pay less than mining, so it could explain a pay gap in some parts of the salary range. Especially in countries like Australia with big resource extraction industries.
Yes, a salary raise in industry A will lead to a salary raise in industry B. Industry B has no option to stop hiring people altogether, so they have to hire at the higher wage level.
But a gender gap in industry A will not lead to an gender gap in industry B. Industry B will just hire the cheaper gender until industry B has no gender gap.
Yes, it improves salaries. But it will improve salaries for both men and women at non-physically demanding jobs.
At non-physically demanding jobs, men and women are competing with each other fairly, so if the salaries demanded by one group go up, the employers will hire the other group until the salaries are equal.