I might not be being relevant here, but I feel that way when some talk about how we could eradicate unemployment.

There are, for better or worse, quite a few professions that rely on unemployed people. I don't know what they call them outside the UK, but here we have jobcentres, run by the civil service and which deal with welfare payments and helping people find work.

Then there are recruitment agencies.

If unemployment was eradicated tomorrow, well there'd be fresh unemployment in a matter of hours when all those jobcentre and recruitment agency workers find themselves without a purpose.

But every once in a while, I think I might like to see a comic where the Flash really does try to handle everything in a split second, or Zatanna uses a spell such as you noted*. The consequences could not only make an interesting story, but it might be a valuable piece of character insight.

I also remember Grant Morrison's message in his first JLA arc. Superman says something on the nature of not doing everything for humanity... that's not why they're there. They have to climb their own ladder. Someone (GL?) asks him, "Then what are we here for?" Superman answers, "To catch them if they fall." That doesn't encompass a super hero's responsibilities entirely... but I like the sentiment.