A character, not a body. Everything else is pushed around by the solver; this capsule is moved by queries: it asks which surfaces are around it and settles where it touches none of them. That is why it stops dead when you release the key, holds a slope without sliding, and slides along a wall instead of sticking to it.
useCharacterBody comes from the adapter, not the format: it is the part of physics a scene cannot write down. WASD to walk, Space to jump.