I get uncomfortable when I read terms like "necessary," "must," "supposed," and "have to" in contexts like this. After-market photo-etched part sets offer a terrific potential for detailing a model. But nobody - least of all me - has the authority to
tell an individual modeler how to build a model.
That Tamiya kit has excellent detail. The doors and hatch covers on the sheets from Gold Medal Models and Tom's Modelworks are outstanding. The details in question are tiny; most people don't notice such things, but some people do. Attaching photo-etched parts to the model is a little tricky; some people find it more enjoyable and less difficult than others do. My only opinion on the subject is that the decision should rest with the individual modeler - based on personal judgment as to what's worth the trouble and the time. If we start letting others
tell us what level of detail is "acceptable" and how much time we "have" to put in on our models, we're on our way toward wrecking the hobby.
Just my two cents' worth. Good luck.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.