This tradeoff doesn’t exist.

Look at Apple’s own smartphone lineup. The Pro models with 120Hz screens get better battery life than the low end iPhone models.

You could make up for the difference in battery life with an almost undetectable amount of extra battery capacity from both a cost and size standpoint.

Even on the 120Hz displays, you can choose to cap them to 60Hz in settings.

Phones use VRR displays, they don't always scale up all the way to 120Hz, only when justified by the content.

the irony is that 120hz screens are actually 1-120hz vs constant 60hz which makes it more battery efficient most of the time except for when you're scrolling

What's magical about 60 there? I'd naively think you'd just want VRR and some power saving render rate behavior rather than a fixed target framerate equal to the max framerate for all types of content all the time. The latter gives you neither good power saving nor good experience in most combinations.

I think you missed the point of their comment. The point is they are reducing features (marginal cost difference for them) to provide a worse experience for a cheaper model. I'm pretty sure it's less complicated to have a shared manufacturing process with fewer SKUs than to have two separate displays (if they're even different and not just software locked).

Do you think they couldn't add a refresh rate control to the device if you wanted to have lower battery? They already have variable refresh rate implemented, a much harder problem.

I remember the age of when Intel used to lock down hardware multipliers for overclocking behind the K versions, and GPUs did too. This is a well known practice, and Apple is not above it.