to be fair, most of them are still working, it's just that most venues turn it off and give us the reason of "not working" anymore so that they're not obligated to restock it with magnetic tuning cards as people might complain they have cards but can't renew, it might also push away potential 6RR customers/revenue because let's be honest, the 3DX+ era is still more fun than what we have now... i knew this because the manager of a nearby Timezone told me this when i asked them about the 3DX+ machine they have.
Yeah, I still have WMMT3DX+ Tuning Cards till now, one of my local arcade have 4 3DX+ Cabinets with working and printable card reader as well as the ability to supply new cards and renew cards.