My old foreman had us using manual miter saws for trim work, and I once cut a board so crooked it looked like a question mark. Took me twice as long to fix it as the whole cut should've taken. That kind of fatigue makes you sloppy, and sloppy costs way more than a new tool. It's not just about being faster, it's about not wasting material and redoing work. A tired crew is an expensive crew, even if the tools seem cheaper upfront.