That statement strongly suggests it's the implementation of the ISA that matters more than the ISA, whether that be due to process node, skill and investment by the manufacturer, or perhaps a bit of luck.

By good ARM, do you mean specifically (and only) Apple? Given their budgets (both financial and transistor), their very long history and investment into their chips, their deep integration of stuff like memory and GPU, and their tendency to be a process node ahead of their competitors, Apple is a particularly hard example to interpret when it comes to ISA impact.

Hard to imagine another company making all those choices, since they all have costs too, which many won't be willing or able to bear, and some of those costs (like the lack of flexibility due to the deep integration) are possibly a non-starter for many niches.