Since graph outputs are often intended to be the final result for a specific texture channel, outputs can be automatically sent to the appropriate sampler of the shader used in the 3D View.
Indeed, an output which Usage property matches a sampler usage in the 3D View will be connected to that sampler. E.g., an Output with a basecolor
usage will be connected to the basecolor
sampler of the 3D View shader. Learn more in the View data in the 3D View section of the 3D View page.
Click RMB on an empty area in the Graph view and select the View outputs in 3D view option in the contextual menu to connect all outputs to 3D View samplers with matching usages.