Poor people are typically less educated and (I guess) are not as well informed about STDs as more affluent people. In countries without a proper healthcare system they are probably also less likely to get STDs treated.

Unwanted children are typically not good for getting out of poverty.

Freakonomics in a way!

Interesting. Didn't think of it like that.

Free contraceptive injections (and reversals that cost a bit) sounds like a great plan for improving quality of life for humanity, actually.

Not OP but argument is likely that condoms are expensive.

Depends I suppose. They're generally free from your local doctor/clinic/sexual health charity in the UK.

There can be a huge social stigma about walking into sexual health clinics. I'll provide an example.

In my city, the old STD clinic was in a random building with mixed use (commercial, health, residential). The clinic was on the 5th floor and not marked. You only really knew it was a STD clinic if you had an appointment there. The clinic moved into a new building and were lucky to expand into a large space. Like many new buildings, way finding is important and the waiting room was marked with Sexual Health Clinic and the elevator level was marked with Sexual Health Clinic. Even though you don't need to use your own name at this clinic, they saw a huge decline in visits since it was quite obvious when someone was attending the clinic. People didn't want to be seen in the Sexual Health Clinic.

Interesting. Generational thing possibly? I'm mid-20's and those kind of things are talked about openly, even in mixed gender company.

Planned Parenthood has a big bowl of them in the lobby. You can walk in there and grab a handful no questions asked. (In the US)