Why GLB is a strong default
GLB packages a glTF scene and its binary and image resources together. That makes uploads easier to validate, cache, back up, and deliver to a browser without a collection of fragile relative paths.
When glTF is useful
A self-contained glTF package can be a good hand-off format for a pipeline that already manages separate files. Make sure every buffer and image is present and uses a safe relative path before uploading it.
Keep materials portable
Web delivery targets physically based materials. Image textures and plain base colors usually translate well; procedural or renderer-specific shader graphs may need to be baked into portable textures first.