Pretty much all industries have invisible labor. You want a good product or service, you need to put the hours in behind the scenes.
Comparing Sex Work with photography is kind of apples and pears.
With Sex work you have low start up costs (comparatively - 250,000yen quoted), a high physical personal risk. You can also price yourself into the market as you are learning the trade (and increase your rates as you get better at it)
With photography (from a outsiders views), you have high start up costs, low personal risk (apart from financial) , and I imagine you need to have experience / skill / training before you are going to sell anything.
No disrespect to escorts, but it seems to me to be an easier profession to get into. But I'd say the physical and mental toll is huge.
I'd compare it more to baseball. There are millions of high school baseball players in Japan. Only about 100 each year make the draft, and of those only about 10-20% will make it to the top team and make real coin. The point being, anyone can play baseball, but to be good at it, you need hard work, and talent. And even then you may not succeed.
