Because with non-remote work like welders you're competing with the local market for welders. Of course if they're paying 30% below market that means they're not properly doing location-based compensation.
It's also a plain idiotic move because you'll end up with workers who cost 70% as much and are half as productive, at best, or at worst workers who cost 10,000% more because they screw up a critical component and cause massive delays.
