Interrupts trash high end cores throughput and they have high latency and non deterministic execution times. Smaller cores like an Cortex-M series handle interrupts quickly and deterministically. And they are very power efficient.

That was a gut feel of mine 30 years ago. And it wasn't as bad then.

Newer gut feel but I remember a processor designer saying the same thing a few years ago. Modern systems the processor very often is doing basically jack all nothing 95% of the time. They aren't very power efficient in that mode. Where Cortex-M processors are.

A soft poke. An Arm Cortex-M4 is as powerful as an 486 of yore that was what people were running windows 3.1 on and playing DOOM.