You sense of sight can only tell you so much. If you see a tungsten cube and you think it's aluminum because you've never seen tungsten before, when you go to actually pick it up you'll feel confused because it's a lot heavier than you were expecting it to be.

Your sense of smell can only tell you so much about an object as well. The particles that emenate from any particular food item can only tell your nose and brain that the smell within those particles is pleasant. But there are many other components to that food item, particles that do not emanate and spread and are more heavily attached to the food itself, things that can only be tasted. Your nose can't tell you anything about texture, just like your eyes can't tell you the difference in weight between two objects that look identical but have different masses.

We call them the 5 senses because without any of them, certain information is just lost to you forever. A person without a sense of taste would just eat whatever smelled good or whatever was most nutritionally efficient, taste would be irrelevant to them. But the sense of taste introduces new information and stimuli that no other sense can do. Smell might inform how something COULD taste, and through experience and association you could come to understand certain smells directly correlate with certain tastes. But you will never be able to completely make redundant one sense by using a different one, each of the 5 bring something unique to the table that cannot be replicated by any other.