Do you mind elaborating on why this approach would be bad in general? It avoids the overhead of creating new classes and wrapping your objects when all you care

Do you mind elaborating on why this approach would be bad in general? It avoids the overhead of creating new classes and wrapping your objects when all you care about is the type-safety that the class would provide. How would you "approach the problem from the way the language lends itself to be solved"?