Battery life is strongly tied to software though, and here Apple has the upper hand. However, if you use Chrome vs Safari, you will notice degraded battery life on Mac OS too.
Still way better than non-M chips.
I've done the runaround and used Safari, Orion, Chrome, Arc, and back to Firefox on my M1 MBP. Some are better than others, but the machine overall is still superior.
Unfortunately, this test didn't include a more recent Macbook, so I can't tell how it stacks up against the M3. Still, for about €500 less than the M2 Air, I know what I would pick. The 1600p screen and the soldered-on memory is a bit of a downside, but the thing sells for less than half the price of a new M2 Macbook Air when you actually configure it with 16GB of RAM and 512GB of storage; whatever improvements the M2 chip made don't seem all that interesting for that price difference.
Based on their historical data [2] for another guide, the Zenbook also seems to beat the M2 in terms of multi core performance and browsing battery life when recorded in another test, but I can't tell if those numbers are representative.
[1]: https://tweakers.net/reviews/11472/4/laptop-best-buy-guide-o...
[2]: https://tweakers.net/reviews/11610/4/laptop-best-buy-guide-d...
https://www.notebookcheck.net/Apple-MacBook-Pro-13-2020-Lapt...
If that Zenbook lasts for 18 hours, it is a good contender. I don't care for having the fastest CPU, just a decent one and plenty of battery life.
For instance, Tweakers uses a screen brightness of 180 cd/m² while testing, whereas NotebookCheck uses 150 cd/m². That alone should account for a sizeable difference in test results. I find it hard to tell what 30 cd/m² means in practice.
Because the ZenBook has a 75 Wh battery, in comparison to the MBA's 52.6 Wh battery. That's one of the reasons it's heavier, too.
I am not an Apple or MacOs fan but I recently bought a MacBook Pro just for battery life. So I can watch movies and browse the Internet on the sofa without having to plug the laptop.