I was trying out. It seems to be an easy way to create a scene without adding to much.
But there is something in the image. The black of the image is not gone.
Then i ask, the resolution of the image has something to do with it, or am I missing something?!
What did you set in the shader settings Blend Mode…? Alpha Clip?
Also…that might not be Black, but a very dark Grey…which will not become invisible in an alpha.