Slop is not about the quality of the rendering, it's about the lack of effort involved in generation. Generation is to creation as bubblegum is to food.
I think putting in low effort to make something which previously would have taken effort, is at high risk for producing slop. It tries to use the effort investment signal to suggest that you have something worthwhile to say, but the signal is fake.
But there are also works of low-key brilliance in the world long before AI, stuff that didn't take a lot of effort (and didn't pretend to) but were great anyway.
It’s a tool. The question is how you use it.