It is really easy to get a fish to move towards a bait/fly/lure but the closer the fish gets to opening its mouth and eating it the odds of the fish deciding to turn away increases. Several things, aside from looks and even action, can close the deal in your favor. Other fish being nearby helps because the competition factor makes them more careless/greedy, this is why bluegill, crappie, and white bass are so easy to catch (once found)..... because they are never alone. Startling a fish by suddenly putting something seemingly foodlike in its face more often than not will cause a loner fish to bite out of instinct, but a fish all by himself will very rarely chase down a lure and end up biting it unless he is nearing starvation OR the bait looks and acts so real (right down to the last millisecond) that it truly fools him. Realistic paint jobs on crankbaits and ultra lifelike looking flys really don't seal the deal IMO, we may have mastered the "look" but there is obviously more to it than that.
Hopefully we never fully figure it all out, cuz if we ever do it will all get very boring very fast. ?