Don't take this for a given. RPis are notoriously bad at idle power consumption. The x86 replacement I bought for my home server ended up having about half the idle power consumption of the RPi it was replacing.
I think maybe you’re overestimating the idle power consumption of modernish x86 (especially the last 5-6 gens of intel)? I’ve a i5 9600T system that’s drawing less than a Pi at idle. And cost me the same to buy.
Our customer don’t really care about power usage much as they are all connected to a TV which draws order of magnitude more power. For some use cases power usage is key, but not for our use case.
And you need to look at longevity, there I suspect ARM will outlive X86 too.
For modularity ARM > X86 too, because they are cheaper to have many small of.
But for scalability (= business in the current economy) X86 > ARM.
Also all graphs should be per watt, that 2 -> 4 is more performant is not news, that it is more performant per watt is!
And if you did that you would see that Raspberry 5 is not getting as much per watt performance increase as it should.
We have peaked permanently for the eternity of mankind.
Let that sink in.
Last but not least, the ONLY hope for any progress (openness not performance) at this point is the JH7110, but they are lagging behind in 3D support.