The blame lies partially on consumers, since as a whole ultimately everyone, you and I, are indifferent. That means that each individual has a near imperceptible role in indirectly contributing to suffering, but still a role. We all accept this trade-off of contributing a bit of harm in order to participate in society. The least we can then do is buy phones only when we need to, something I am committed to. Buying used would be even better. I have to disagree when you say that the consumer is the problem. They're a part of it, but it should be obvious that the main issue lies with the companies and what makes up their supply chains. An individual or even a group ditching their phones will not solve this issue, only if literally entire populations does can the consumer change things, which is totally infeasible as of now. Rather, the responsibility now largely lies with companies, as they have a much more direct role in perpetuating the suffering and have the means and resources to alleviate it. And the good news is that some have taken some action, as shown here: https://www.amnesty.org/en/latest/news/2017/11/industry-giants-fail-to-tackle-child-labour-allegations-in-cobalt-battery-supply-chains/. It is now our responsibility as consumers to not support those that do nothing, as now there are differences between the companies.