There are a lot of theoretical articles which claim similar things but on the other hand we have a lot of empirical evidence that ARM CPUs are significantly more power efficient.

I used laptops with both Intel and AMD CPUs, and I read/watch a lot of reviews in thin and light laptop space. Although AMD became more power efficient compared to Intel in the last few years, AMD alternative is only marginally more efficient (like 5-10%). And AMD is using TSMC fabs.

On the other hand Qualcomm's recent Snapdragon X series CPUs are significantly more efficient then both Intel and AMD in most tests while providing the same performance or sometimes even better performance.

Some people mention the efficiency gains on Intel Lunar Lake as evidence that x86 is just as efficient, but Lunar Lake was still slightly behind in battery life and performance, while using a newer TSMC process node compared to Snapdragon X series.

So, even though I see theoretical articles like this, the empirical evidence says otherwise. Qualcomm will release their second generation Snapdragon X series CPUs this month. My guess is that the performance/efficiency gap with Intel and AMD will get even bigger.