One of the many reasons why snapdragon windows laptops failed was both amd and Intel (lunar lake) was able to reach the claimed efficiency of those chips. I still think modern x86 can match arm ones in efficiency if someone bothered to tune the os and scheduler for most common activities. M series was based on their phone chips which were designed from the ground up to run on a battery all these years. AMD/Intel just don't see an incentive to do that nor do Microsoft.