Newer Intel Panther Lake chips perform the same or very similarly on battery as they do when plugged in - as do Qualcomm chips. However, I don't know where they're seeing "consistently beat on performance and battery life by Intel Windows laptops". Multi-core performance can definitely beat M5 in some configurations but single core performance is still fairly far behind and battery life is comparable again depending on the exact specifications and design of the laptop. I've seen analysis showing M5 is still the perf/watt king though regardless of configurations.