A lot of doors from the 1960s through the 1980s are still running on original torsion springs and the same steel track they shipped with. That does not mean they are worth fixing forever. If a door is from the early end of the build range and the opener has already been replaced once, a second opener failure plus a spring issue on the same visit usually means a full swap beats another patch.
Freeze-thaw winters here put real strain on springs, and that is usually when a marginal spring finally snaps instead of just sagging. If we are replacing a spring on a door already dealing with a bent track, worn rollers, and a tired panel, we will say so: throwing one new part on a door held together by the other three is not a repair, it is a delay.
A cracked panel on an otherwise sound door is the opposite case, and almost always worth fixing rather than replacing, especially on a double door where swapping one section costs a fraction of a full door. We would rather tell you a door is done than keep billing you for pieces of it, because that is the call that saves money over two or three years instead of costing more.