People don't want to sell their personal data for currency.
People need currency. There is only a finite amount of currency in the world. Power structures are formed because some people have currency and other people need currency.
People are forced to do things like sell their bodies, sell their organs, and - yes - sell their biometric data. Because they need currency to survive. You don't see billionaires lining up for this.
It's exploitation of those who are most desperate. You can argue that there's the systemic problem - that there shouldn't be billionaires alongside people who are starving and need to sell their bodies - but that isn't being solved anytime soon.
But exploiting this systemic problem, using it as leverage to convince millions of poor folks to sell their biometric data... that's immoral. It's immoral to take advantage of desperation just to line your own pockets.
Why do you think you're hearing about this from some of the poorest countries in the world?