Part of it might be new battery effect too. I just popped a new battery in my 2012 and just doing light dev work I could stretch it to 8 hours or so. This thing was doing like 3 hours on a good day before.
Certainly that plays a part. But my M1 Air is now over a year old and I can still easily edit 4K video in iMovie for a few hours and see the battery only drop from 100% to 70%.
Pretty huge! Don't expect miracles long term though. Batteries are still batteries M1 or not and if you do 4k video editing every day, you will notice wear over time. What sucks about the new macs is you need to take it in to replace a battery, where as you used to be able to do it yourself in like 2 mins or less.
