Where MIG wins
On mild steel above roughly 1/8 inch, MIG usually delivers the same structural result as TIG at a fraction of the arc time. For frames, skids, brackets, guarding and machine bases, it is normally the cost-effective answer.
Automation and repeatability
MIG adapts well to robotic cells and positioners. If your part is stable and you expect recurring releases, ask shops what it would take to move from manual to automated welding — including fixture cost, programming time and the volume where it pays back.