I think most people agree in the deep learning community that ways to understand NN's are useful, if for nothing other than debugging, but I don't think the community agrees at all over whether explainability is necessary to use it. In many cases, it depends on the context. For self driving cars, most companies only use neural networks for components of the cars and an explainable algorithm on top of that that interp…
Maybe? You'd have to convince me in areas as medicine. Why are you recommending this treatment path? "Dunno. The computers says so."
Mind you, the doctor may well not in reality have a lot more solid basis for his recommendation. But at least there's the appearance of logical justification.