Not always. Carpet soaked by clean water can often be extracted, dried, and saved if you move fast, though the underlay underneath usually cannot. Drywall that wicked clean water is sometimes dryable in place with the right equipment. Anything touched by contaminated water, sewage or prolonged flooding, is a different story. That material comes out. No drying protocol makes Category 3 drywall sanitary again.
The honest answer comes from moisture readings, not from eyeballing the stain line. Nonstop Restoration maps how far the water actually travelled using moisture meters and thermal imaging, then documents what can be saved and what cannot, in the format your adjuster needs to approve the scope. You do not pay to replace material that was salvageable, and you do not keep material that will grow mold inside your walls.