• No, that’s not why.

    I mean, it wouldn’t be cheap, but it would also be utterly nonsensical. So you put a tracker on a container and it sinks somewhere. Then what? First of all, this would have to be a satellite device (costly per container, then consider that thousands that fit onto a single ship), which needs sensors to detect it’s going overboard and then send out its position before it’s submerged. Maybe something communicating with the ship instead of satellites would be a little cheaper, but it’s equally pointless, because the container wouldn’t sink in a straight line and burst open long before it reaches the bottom.

    Average ocean depth is 3,682 meters (12,080 feet). Nobody will go on a costly underwater expedition using one of the maybe ten or twenty civilian submarines on the entire planet (each worth tens of millions) that can handle this kind of depth without imploding to recover some soggy Chinese fast fashion garbage or crushed iPhones (because the pressure down there is about 366 times as much as at sea level - I don’t think Apple rates their devices for that). Even if you do, you’d need a lot of trips picking up future landfill fodder with a little robot arm to get even close to getting all of the up to around 25 tons of former cargo.