> this would have prevented so much e-waste...
E-waste is effectively profit for the device manufacturer. Discarded phones mean that the whole portable computer that is still more powerful than what we had in universities 20 years ago has become worthless and needs to be bought again. It's created an income stream for the manufacturers -- and that's why they're not incentivised to fix these problems. I'm using a OnePlus 5 -- officially EOL and Obsolete! -- with modern LineageOS Rom and it flies. Of course, "official" apps don't like that at all (which is downright stupid of its own reasons), but I have got around that.
I'm sure OnePlus would rather that I threw the thing away and bought another shiny model to get Android 11. Frankly, I'll use it until it breaks and hope that the FairPhone people have caught up by then...