@pluralistic Around 12 years ago, I lost my baggage on a multi-stop flight through CDG. Although the airline responded (in an automated way), they obviously spent no efforts in actually finding the baggage. Apparently, it was considered cheaper to just pay the damages.

I didn't give up at this point, but looked up all subcontractors for baggage handling of all involved airports. I sent e-mails with a detailed description of my baggage to them. Surprisingly, I actually got responses by humans - and one of them was even able to track down my baggage! A few weeks later, I had it back in my hands.

Wonder if that still works in today's world of deteriorating service quality, but I'd definitely give it a try.