Why does it need to be Android? Make a phone that will send text messages and run a web browser and all the people who just need a phone will buy it to save $200.
Also, when software is poorly optimized that implies it is possible to optimize it.
For a start, most of the world does not use text messages. They use WhatsApp. (Apart from a few countries where WeChat, Telegram or Line are more popular.) As far as I know the US is the only country that still uses SMS/RCS.
> Why does it need to be Android? Make a phone that will send text messages and run a web browser
I think we're quite a ways past the point where most people would be satisfied with phones that only do voice, text, and web browsing. People have become quite accustomed to phones that can run arbitrary applications and games. There's quite a sizable population for whom phones are their only computing device.
Web browsing is the most resource intensive task given how bloated modern websites are. It’s easer to imagine a cheap phone with a set of optimised native apps but the problem is tech giants are not interested in reducing footprint of their apps at the same time actively hostile to 3rd party clients.