It's great that Fair Phone is doing this, but this shit should be required by law. Products built below the safety, environmental, or labour standards of a country should be subject to tariffs on entry.
Otherwise it's just us rich assholes exporting shitty working conditions.
The Fairphone strategy is also basically an advertisement. We should never trust a company to give an accurate impression of what they are doing when it is part of their marketing. They have every incentive to present the best possible face. Their product depends on feeling like you are doing good by buying it. And often, doing less harm means spending more money, decreasing their own profits, so companies will give a rosie picture and not mention, say, their complicity in union busting or worse or how much more the (inevitably OECD) executives and VPs pay themselves than the people who actually build the product.
If workers owned and controlled the production facilities we could feel a bit better about it, as they would be able to at least advocate for themselves.