You understand you don't need to be nude for onlyfans right? It's not a scam. Y'all are just desparate for dick and mad when it's not shown. Your own fault if you spend money on that site. Unless they explicitly say they show full nudes, it's a you issue being let down.
You're correct that OF accounts don't have to show nudity. Nobody is obligated to show more of themselves than they want, and nobody is entitled to see nudes of anyone else, whether private or semi-public figures.
However, what is occurring with many OF accounts is not without context: creators know that the audience is hoping for, if not expecting, nudity/porn. This is especially true when the sole reason for the creator to have an OF account is to show off their body (it's not like they're doing cooking tutorials). Therefore, when the creator charges real money for various photos or short clips with suggestive descriptions, they are doing so in an effort to take advantage of their audience. The intent is to trick the audience into assuming the content shows nudity, with full knowledge that if the audience knew there wasn't nudity they'd be far less likely to purchase the content. This is in fact a form of fraud, even if it's perfectly legal.
We also need to compare the cost of OF accounts to the cost of actual porn, were one to subscribe to a porn website or group of sites. Double-digit monthly fees, with additional double-digit fees for individual pieces of content, carry with them a set of expectations from the audience in terms of content quality. Generally, people are going to define "quality" in this context as including explicit content, large quantity of content (long videos, lots of photos), in addition to basic quality that we often take for granted (visibility, picture sharpness/lightning, sound, etc).
A single person, or even someone who's OF account is being managed by some firm, may not be able to provide the quality of content that a commercial porn site can (although the OF audience is often paying for the amateur feel and tone; the "girl/boy next door" concept). But it's not unreasonable to expect that, for such a high price, the payer will be receiving content that meets their expectations. Shirtless photos that could be found on instagram or twitter are obviously not going to meet those expectations, so you can expect that customers will complain.