Some jobs like bar work or physiciatric work carry risks of physical altercation etc.

In prostitution the physical encounter is the whole job, there's no avoiding it. Your body is the product.

Sex itself is also highly exceptional emotionally. Your body reacts to sexual behavior neurochemical in a way that's incomparable to really any other activity, and it's unique in how it can affect your relationships and self perception.

Please note that I make No judgement against sex workers when I say this.