Yup, the idea that components can be reused is absurd.
While re-using parts soldered onto PCB's is usually not practical, there certainly ARE components such as keyboards, displays, and drives that could well be re-used. But that's not even the real point - in may cases we're talking about fully functional devices that are being shredded. That's outright fucking criminal. Each device represents a huge investment of energy - therefore each device should be used as long as it works and someone wants it. Destroying fully functional equipment 'because business' or 'because shareholders' is stupid, shortsighted, and immoral.
Repair is likely to cost as much as buying a new one...
'Uneconomical to repair'? Most often these days, that's a pile of contrived bullshit. Manufacturers set it up that way. They do so partly by purposely making equipment difficult or impossible to service, and by charging scandalous prices for replacement parts. They also do it by having artificially low prices for their goods. If the REAL costs were factored in, (depletion of natural resources, environmental damage, climate change, the human costs of slave labour, etc.), goods would be much more expensive to purchase, as they should be. Repairability and longevity would then be not only cost-effective, but necessary, and the market for used equipment would be huge. Instead, we have companies fattening their bottom lines at the expense of future generations, in the service of a Ponzi scheme of an economy whose only guiding principle is "more growth is better, and unlimited growth is best". Which, incidentally, is the guiding principle of cancer, infections, and a whole host of other similar phenomena which rob human beings of life and dignity.