Having mechanisms like this in place unfortunately makes it easier for others to abuse them for DRM.
There is a lot that can be done and there is a lot that people do.
As individuals we can of course offer mere anecdotal evidence. Coming from Belarus, I can say that the amount of talented hackers repurposing old tech was always strong there, though I don't have a strong connection there anymore. I recently covered the QuadCore mod for ancient thinkpads and the firmware replacement that entails: https://youtu.be/Fs4GjDiOie8 I received multiple requests on Details and Walking through individuals performing similar upgrades from Latin America. To me, the spirit for reviving trash grade tech to our modern sensibilities is alive and well.
The issue is that most phone manufacturers don't allow owners to do this, and most that do, do pull shenanigans that make it unpredictable and difficult.
Poorer people would absolutely choose to pay 25 dollars to extend their phone's life (replace battery + reflash to a supported firmware/os) vs buying another 200 dollar phone.
I'm hoping the EU (and the rest of the world) steps up and does what the US should have done a long while ago.