The ultimate reason is there isn't economic reason so. It cost's a lot to recycle anything, and most electronics would net you almost nothing valuable.
Let's look at an example. Let's say your phones main board, which will net a few hundred grams of raw materials. First thing by weight the actual board itself is probably the biggest, if you could perfectly decompose it to it's parts you would have some fiberglass, glue, a few grams of copper, and maybe a trace amount of gold. Next you would have the different components, mostly ICs but let's cover them next. These are mostly plastic with bits of copper, tin, and other more exotic metals. Most of these could be used again, if you can separate them and sort them. There would be a bunch of solder, which maybe could be reused, if you remix it with more flux. Finally, you'll have chips, these could be reused, but only as replacements for the same chip. Getting anything out of these would mostly be removing the bulk of the material which is silicon that's been contaminated with other elements to make the semiconductors. I don't think there is any process right now that could take doped Si and get you anything back. Besides the silicon you have micrograms of gold and other conductors.
Having put all that down, I think there could be an opportunity to take the bulk components off boards, test and sort them, and sell them in bulk.
True, it's the reason why most items aren't recycled. By far most items are buried or burnt rather than recycled. Our economic system is setup to minimize the manufacturing costs without considering disposal cost unless it's mandated. I don't think recycling will every be a real thing unless disposal costs become part of the overall price of manufacturing an item. Something that's mostly impossible unless it's mandated and people decide that trash is unacceptable or at least needs to be greatly minimized. Thinking about it, maybe at some point disposal cost will become so expensive that people won't buy new items unless sellers pay for trashing them.
2-3% of 1 ton is 40-60 pounds of gold, and that's using the smaller, non-metric tons. 200g is about half a pound, so you'd be looking at 80x more gold per ton from traditional mining on the low end
And the gold in electronics is usually in microscopically thin layers, so it only makes commercial sense to extract it when other sources become more expensive... and at that point, doing an ecological extraction won't be a top priority.
Really, the reduce and reuse parts are our best bet, because recycling only delays the inevitable, unless some groundbreaking technological change achieves 100% electronics recycling.
"Indeed, a natural ore mine can produce 5 g of gold (Au) per ton of ore, while 200–250 g Au can be recovered from the same mass of computer boards (300–350 g Au/t for mobile phones) [6]."
"Indeed, a natural ore mine can produce 5 g of gold (Au) per ton of ore, while 200–250 g Au can be recovered from the same mass of computer boards (300–350 g Au/t for mobile phones) [6]."
Where in the world would that be true? That would be 800 - 1000 ounces per ton! As far as I know the best pay dirt produces a handful of ounces per ton, or 0.01%.
"Indeed, a natural ore mine can produce 5 g of gold (Au) per ton of ore, while 200–250 g Au can be recovered from the same mass of computer boards (300–350 g Au/t for mobile phones) [6]."
Let's look at an example. Let's say your phones main board, which will net a few hundred grams of raw materials. First thing by weight the actual board itself is probably the biggest, if you could perfectly decompose it to it's parts you would have some fiberglass, glue, a few grams of copper, and maybe a trace amount of gold. Next you would have the different components, mostly ICs but let's cover them next. These are mostly plastic with bits of copper, tin, and other more exotic metals. Most of these could be used again, if you can separate them and sort them. There would be a bunch of solder, which maybe could be reused, if you remix it with more flux. Finally, you'll have chips, these could be reused, but only as replacements for the same chip. Getting anything out of these would mostly be removing the bulk of the material which is silicon that's been contaminated with other elements to make the semiconductors. I don't think there is any process right now that could take doped Si and get you anything back. Besides the silicon you have micrograms of gold and other conductors.
Having put all that down, I think there could be an opportunity to take the bulk components off boards, test and sort them, and sell them in bulk.