Repair is honest when the failure is local: a shifted cap, one cracked course, a clogged weep hole, on a wall still standing plumb. A wall leaning past plumb, cracked through its structure, or bulging from failed drainage is a rebuild, because the cause has to be fixed, not the symptom.
More detail
The repair-or-rebuild call comes down to one question: is the wall's structure still doing its job, or has the load already won? Signs that favor repair: the wall stands plumb, the crack is isolated (a corner, a single course, a cap row), the footing has not moved, and the drainage behind the wall still works or can be locally restored. Those are maintenance events, and pricing them as maintenance is the honest answer. Signs that end the conversation: a lean you can see or measure (a wall past plumb is being rotated by pressure it cannot resist), a horizontal or stair-step crack running through the structural courses, a visible bulge or belly, soil washing through the face, or a wall whose backfill was native clay with no drain, because that wall is fighting a load it was never built for and every wet season moves it further. Patching a leaning wall buys appearance, not time. The rebuild scope does what the original should have: correct footing, engineered structure where height or surcharge demand it, gravel backfill with fabric and a drain that daylights, and surface grading that routes water around the wall instead of into it. At the walkthrough we measure the lean, probe what is behind the wall, and tell you plainly which side of the line your wall is on, with a written fixed price for that answer rather than the bigger one.