Given that videos spin up those coolers, there is actually a problem with your GPU setup on Linux, and I expect there'd be an improvement if you managed to fix it.
Another thing is that Chrome on Linux tends to consume exorbitant amount of power with all the background processes, inefficient rendering and disk IO, so updating it to one of the latest versions and enabling "memory saving" might help a lot.
Switching to another scheduler, reducing interrupt rate etc. probably help too.
Linux on my current laptop reduced battery time x12 compared to Windows, and a bunch of optimizations like that managed to improve the situation to something like x6, i.e. it's still very bad.
> Is x86 just not able to keep up with the ARM architecture?
Yes and no. x86 is inherently inefficient, and most of the progress over last two decades was about offloading computations to some more advanced and efficient coprocessors. That's how we got GPUs, DMA on M.2 and Ethernet controllers.
That said, it's unlikely that x86 specifically is what wastes your battery. I would rather blame Linux, suspect its CPU frequency/power drivers are misbehaving on some CPUs, and unfortunately have no idea how to fix it.