If you fully load the CPU and calculate how much energy a AI340 needs to perform a fixed workload and compare that to a M1 you'll probably find similar results, but that only matters for your battery life if you're doing things like blender renders, big compiles or gaming.
Take for example this battery life gaming benchmark for an M1 Air: https://www.youtube.com/watch?v=jYSMfRKsmOU. 2.5 hours is about what you'd expect from an x86 laptop, possibly even worse than the fw13 you're comparing here. But turn down the settings so that the M1 CPU and GPU are mostly idle, and bam you get 10+ hours.
Another example would be a ~5 year old mobile qualcomm chip. It's a worse process node than an AMD AI340, much much slower and significantly worse performance per watt, and yet it barely gets hot and sips power.
All that to say: M1 is pretty fast, but the reason the battery life is better has to do with everything other than the CPU cores. That's what AMD and Intel are missing.
> If I open too many tabs in Chrome I can feel the bottom of the laptop getting hot, open a YouTube video and the fans will often spin up.
It's a fairly common issue on Linux to be missing hardware acceleration, especially for video decoding. I've had to enable gpu video decoding on my fw16 and haven't noticed the fans on youtube.