A dented panel on a newer door rarely fails on its own, but it doesn't stay isolated either. Steel sectional panels lock into the tracks and hinges at both ends, so a bent panel can pull the roller out of alignment on that side, and a misaligned roller wears the track faster than it should. On a two-car door, a crack that runs the width of one section can also throw off the balance the opener depends on, which shows up as the opener straining or reversing partway up. None of this is dramatic on a 20-to-25-year-old door the way it would be on genuinely old hardware, but it's still real wear, and ignoring a cracked panel for a season or two turns a one-panel job into a two-panel job.