I go to a nudist resort fairly frequently. Most of it is clothing optional except for the pools, so you see people walking around in various states of undress depending on the weather and what they're doing (watched a guy weedwacking naked last time I was there, seemed ill-advised IMO)

You pretty quickly stop seeing nudity as being sexy there . It certainly doesn't help that the average nudist is middle aged or older and often not in the best shape.

This resort also attracts a decent amount of swingers. While the nudists aren't particularly trying to impress anyone, that's pretty much the whole reason the swingers are there. So how do you make yourself look sexier than just walking around naked? You wear something. Bathing suits, pasties, big flashy jewelry, crazy hats, see-through dresses, ropes, etc.

And though many of them aren't much more attractive than the nudists, they turn some heads.

See also: https://tvtropes.org/pmwiki/pmwiki.php/Main/TheissTitillationTheory : "The sexiness of an outfit is directly proportional to the perceived possibility that a vital piece of it might fall off."

Exactly. I see a bikini every time I see people swimming. Underwear though, that implies some form of intimacy

There was an old Piers Anthony series about a society where the masses, mostly slaves, went naked and only the owner class could wear clothes. The more clothes, the sexier.

To summarize your statement, social conditioning

This makes zero sense to me. It's all just cloth. The person in a g-string & harness is, literally, less exposed. You're conflating the context of "being exposed" and "adds to the exposure". Those two phrases mean different things. The first is referencing how much skin is visible while the second is referring to how noticable and attention-grabbing the individual is. You would be arguing an entirely irrelevant point to what was being discussed in your own hypothetical

Clothing being "suggestive" is entirely a subjective concept. What is "suggestive" to you might just be something the other person finds comfortable. It is also the same general logic behind "look at what she is wearing, she was asking for it" and I find that really problematic.

The underwear example is also just dumb to me. It's just cloth. It isn't "meant to not be seen", it's just there to avoid regular clothes chafing sensitive areas of the body. It being seen is irrelevant and simply a coincidence of being worn under other articles of clothing. There are no inherent, underlying implications except for what you put on them through your own bias.

This just reaffirms for me that people like to add arbitrary, subjective aspects to things and then try to assert these as intrinsic facts instead of personal biases.

Is anybody shocked to see a nude statue in a museum or something?

Sadly, some are. I remember as a teen visiting my aunt and uncle who had a giant Catholic family. We were sitting around watching one of the Pink Panther movies, where the main character is in a museum at night. As he scans his flashlight across the room, it passes over some nude Greek statues. My aunt took the remote and switched the channel, saying "We don't need to watch this smut."