Why are atomic models necessary?
Atomic models are necessary because atoms are too small for us to see.
So we do experiments. From the results, we make a guess about what an atom looks like.
Then we do more experiments to test that guess. From those results, we modify our guess, and the process continues.
The models enable us to make predictions about chemical bonds, molecular geometry, reactions, etc.
The predictions may not always be accurate. Then we have to do more experiments to explain the results.
Fifty years from now, there will have been new discoveries about the atom. Future models of the atom will probably be quite different from those we know now.