Well they don't say what happens to the shoes that are in bad condition, I think for completeness' sake they should do the same with tatty and worn out shoes. The trackers would likely get shredded then though.
I think this is only half the story. Why would they shred up perfectly serviceable shoes when they can make money off of selling them?
From memory, and this may have changed in the last 10 years, Indonesia doesn’t really do “rubbish dumps”. They sweep everything in the street, including rubbish from peoples homes into small piles and burn it there and then. Might be different in Jakarta but this is what I saw everywhere else. The smoke and smell of burnt plastic was everywhere. I only spent a month there but I got around a lot and on more then one occasion witnessed Malaysian tourists asking Indonesian locals why there was rubbish everywhere. No bins hey. The national parks were (still are?) especially bad. Anyway, Indonesia is probably not the best final destination for any sort of waste.
IMO, Indonesia is not the problem, its really the farce of plastic recycling.
I think this is only half the story. Why would they shred up perfectly serviceable shoes when they can make money off of selling them?