I think the issue with these low end devices are that the duopoly on operating systems makes it impossible to develop a competing operating system that get's any traction.
I am 100% sure you, as a manufacturer, could develop a very lightweight shim over a linux or BSD kernel that has significantly better performance than Android does. It would however be a universal flop regardless of how useable it is since critical apps like WhatsApp/Telegram/banking would not get ported to that platform ever.
That effectively leaves you with needing a capable web browser and well... Even Firefox with every form of adblocker enable regularly chews up 2-3 GB of ram for me, at least on desktop. And building a competitive web browser to Chromium is an absurd endeavour for a cheap cell manufacturer.
I am 100% sure you, as a manufacturer, could develop a very lightweight shim over a linux or BSD kernel that has significantly better performance than Android does. It would however be a universal flop regardless of how useable it is since critical apps like WhatsApp/Telegram/banking would not get ported to that platform ever.
That effectively leaves you with needing a capable web browser and well... Even Firefox with every form of adblocker enable regularly chews up 2-3 GB of ram for me, at least on desktop. And building a competitive web browser to Chromium is an absurd endeavour for a cheap cell manufacturer.