Laptop battery life suffers greatly on Linux. When their Google Chrome bootloader is out of battery all day, it matters which OS they installed.

Doesn't matter though. Every single one of these "casual" users I know has a terribly outdated device with a broken battery that doesn't even charge anymore.

And I agree: if it works, why replace it?

People who care deeply about unplugged battery life aren't on Windows to begin with.

This doesn't make much sense, ChromeOS is itself Linux, and those are prime "computers for parents" machines.

not the same thing at all. Different userspace that may or may not be that efficient at power, as well as well tested power management in the kernel for specific devices.