This is whats frustrating to me. We're talking a small slice of most chromebooks out there.
I actually have used old chromebooks with crouton to install steam and play games. You have to pick "lightweight" games like Baldurs Gate, but it still opens up a lot of possibility.
So I had hoped maybe something could be brought to old hardware, but I guess not.
I think you start by targeting the platforms with more horsepower and can move down over time. Obviously they might just not do that work and stay on the high powered ones, but I don't think it's a given.
It's a small slice today, but today's high-end computers are tomorrow's cheap used machines, and future budget machines will be more powerful than present high-end ones.