And you're completely right. As someone that lives in Kenya and has used these apps, I can count in one hand the number of apps that I consider 'ethical.' The kinds of interest rates they charge are seriously absurd and some go as far as charging 10% interest
per day that you're late paying the loan :/
On the bright side, while there are over fifty of these shady apps, most loans (including on mobile) - something around 84% of them, if I remember correctly, are still issued by banks.
But overall, another issue it raises is the reason Kenya (I'm not sure about other African countries) is really slow in innovation in the software field. Tala was one of the first loan apps to be released and it remained like that barely for months. The next thing you know, there are over a dozen of them and new ones keep getting released every year! It's mad!
The same thing happened with SportPesa, a gambling platform that later quit the Kenyan market. Once people realized SportPesa was profitable, the number of copycats went through the roof. Competition isn't a bad thing, sure, but once they really hit the mainstream, it's insane how many people would rather copy something that works than try something new themselves.