Yes but, they are.
They are supporting fair mining projects and contributing to players that certify fair mineral sourcing.
And they're raising awareness in the process.
https://www.fairphone.com/en/2021/02/08/fair-mining/
I've seen some videos of ASM lithium mines, stuff is nightmare inducing. The videographers spotted a handful of children in the hills trying not to be seen.
I think it's doable, it'd be similar to setting up and auditing your own green coffee beans; it wouldn't be particularly capital intensive.
"We are working with our battery supplier to integrate lithium from IRMA-assessed mines into our battery supply chain" this line could mean anything from actually doing something to "we sent one email". Before you believe that someone is making a difference, be sure they are. Fp is not.