Why a patched wall still shows
Drywall fails in a handful of ways, and you likely know most of them already. A doorknob goes through the wall behind a door. A crack opens at the corner of a window or along a tape seam, and it comes back every time you caulk it. Nail pops rise like small blisters where a fastener backed out as the framing dried. A brown ring spreads on a ceiling after a leak.
The hole is rarely the hard part. Patches fail at the finish. Compound laid on thick shrinks and cracks. An edge that wasn't feathered wide enough throws a ridge you only see when afternoon light rakes across the wall. A smooth patch on a textured wall glows like a bandage. And paint alone won't hold back a water stain: it bleeds through the new coat until the stain is sealed, and a ceiling that got wet has to be dry and checked before anything covers it.
