What you need to decrease the number of prostitutes is actual jobs that can actually pay you a decent living,
That's not going to eliminate prostitution, though it would likely increase the price and somewhat reduce the number of providers. The demand for prostitutes will always be huge, simply because a very large minority of men can't get sex any other way, and many of them will be willing to pay a very high price for this service.
The typical result of 'development' in an economy (theoretically, 'higher wages') is that men still visit prostitutes, but simply pay much more and go less often. But the basic need is still there and will not go away.
If you care to actually
read what I posted, you'll remark I said "decrease" the number of prostitutes, and not "eliminate prostitution". I used this term exactly because of the argument you made.
