Simple WAV conversion does not add missing detail. Conversion in tools like Audacity mostly repackages existing samples through interpolation, while True Audio Restoration uses generative AI (similar to image super-resolution) to predict and insert missing detail, recovering dynamic range and "air" lost to compression.
Use Audio Restoration when the source is muffled, bandwidth-limited, clipped, or damaged by lossy compression. Read the MP3 upscaling guide for more context.