The explanations for why certain actors go to painstaking lengths to avoid showing skin on-camera vary from person-to-person, and of course, it’s often for personal reasons.
After all, nobody should be obligated to take off their clothes and some people just aren’t comfortable being in-the-buff, particularly on a set.
There are also actors and actresses in Hollywood to make sure that “no nudity clauses” are written clearly and explicitly in their contracts.
In Hollywood, it’s often common practice to hire body doubles or find creative or unique means to prevent the performer from performing scripted nude scenes.