I think we can look to mobile to see how feasible this might be: consistently over the past decade, iPhones have matched or exceeded Android performance with noticeably smaller capacity batteries. A-series chips and Qualcomm chips are both ARM. Apple's tight integration comes with a cost when it comes to flexibility, and, you can argue, developer experience, but it's clearly not just the silicon itself that leads to the performance we're seeing in the M1 Macs.