Even smartphones hit a point of diminishing returns after a while. A 5 years old Samsung Galaxy S8 would be still perfectly usable, and better than most cheap devices today, it's just unsupported, because go buy the new one. Fortunately you can slap a ROM on it and keep using it, you can even replace the battery. Unfortunately millions of these devices are already chilling on a landfill somewhere. It's not like we are running out of the resources to make new ones, or there is an environmental collapse looming around.