Sigh.
Why are people even surprised? This won't change and can't change until we stop yelling "think of the children!" and only demanding for the suppliers to do a better job.

Yes some suppliers might be able to do a better job but many cases they also simply can't it's just the nature of doing business with under-developed countries.

Similar processes like the Kimberly process that was supposed to stop the trade in conflict diamonds have utterly failed and this is an industry that is built around artificial scarcity which just was dying for an excuse to further limit the production of diamonds to jack up the price.

There is very little any supplier can do to actually address this problem, this isn't some large scale mining operation that uses children this is for the most part unofficial mining.
Unofficial mining (AKA the official past time of small scale African warlords) is pretty much a bunch of people taking over abandoned mining sites, dump sites for mining waste, sites that were deemed to be uneconomical to develop or just being down stream from the actual mine.

While it's true that these sites are often taken over by some gang of former child soldiers and their master (we all liked Beasts of No Nation) more often than not these days unofficial mining is conducted by communities, villages, and individuals who do not hold any one at gun point.

These unofficial mining operations do not produce any substantial amount of note (individually, however there could be 1000's of small scale mining operations vs only a handful of large scale official ones which means that anywhere between 10-50% of a given product might be mined unofficially) but they do produce enough to say feed a village (or to buy the wanna be warlord a BMW from the 80's even diamonds are sold for not even cents on the dollar, every 1$ in uncut stones that ends up in the hands of the miner is inflated to 1000 to 10000 by the time it ends up at tiffany's).

Those unofficial mining operations are getting mixed with what the big actual mining operation produce and end up in the supply chain, this can happen at so many points that there is no way to enforce any process which will guarantee that the supply is clean of conflict, child labor or any other social decree.

Even if you take out the child labor part which while horrid is by far not the worse part that can happen to a child in Africa, the conditions in the official mining operations for registered adult miners are also appalling and so far beyond what most of us could even imagine human beings being able to withstand on a daily basis.

So instead of yelling that we should vote with our wallets until those supply chains will be clean we need to realize that they will never be clean as long as you are dealing with a region such as the Congo.
Instead of making another pointless process which will just going to be circumvented at all levels while jacking up the price for the end consumer (which every one in the supply chain, especially as it gets closer to the source will just pocket the difference).
Companies should put the money that consumers would end up paying into programs that might actually work and not into the endless pit of bribes that any certification process would turn out to be when facing the unmovable object which is reality.

Apple can switch a supplier and it will, but it won't find a clean one as no such supplier exists even if they'll find the most expensive one with the best intentions. Because the local population which runs these operations will always have the upper hand and as long as the conditions exist that make it more likely for children to end up digging up rare earths for your smartphone or diamonds for your tennis bracelet this won't change.

I hope the day would come where a company like Apple could be brave enough to come out and say look we can't buy Cobalt which wasn't mined by kids, but we made a calculation that if we could it would be 17% more expensive so we are jacking our own prices by 17% and transferring the difference to X Y and Z in hopes that in 20 years we could buy Cobalt which was not only not mined by children but also mined by miners with life expectancy which is longer than our yearly product cycle.

But as long as people would keep on yelling boycott this and boycott that it will never happen and the only thing Apple can do is to continue to play the pass the hot potato game with it's suppliers (which will continue to restructure and change names to be put back into that list) and maybe have Tim Cook do an apologetic we are the world cover...