[chillacy]

1. Black-Scholes works in a lot of cases but is an approximation: it has edge cases where it does not fare well...

2. Likewise Newtonian physics is also an approximation: it does not fare well near relativistic speeds or high gravity. But at least we have models which seem to be accurate to many decimal places today. Who knows what the future may hold.

3. Not all useful problems can be represented by simple equations, but they can be computed analytically (e.g. N-body problem).

4. Ultimately DL is popular because it works better than anything else in some very specific domains like speech recognition and image recognition. It is overapplied I'll admit, but if you can do better then feel free to publish a paper.