The M1 MacBook Air can run a whole day (and more) on one charge, but „only“ 5h when doing heavy development with Xcode. If you build a machine that lasts 2x as long with 10x the power, I‘ll pay at least 5x the price for that. Maybe 10x.
This feels like a bad deal for Apple.
If you wait - you’ll get a 20x machine at current prices.
This is what Moore’s law is about ? I.e. Density (~= proxy for compute) doubling at some fixed period.