arithmetic is a very small and almost inconsequential skill to develop within the framework of mathematics.

I'd consider it foundational. And hardly small or inconsequential given the time young people spend mastering it.

Any human that doesn’t have severe learning disabilities will be able to develop a sufficient baseline of arithmetic skills.

With time and training, sure. But simply handing out calculators and cutting math teaching budgets undoes that.

This is the real nut of comparison. Telling kids "you don't need to know math if you have a calculator" is intended to reduce the need for public education.

I’d be a lot less bothered if LLMs were made to provide guidance to students, a la the Socratic method: posing leading questions to the students and helping them to think along the right tracks.

But the economic vision for these tools is to replace workers, not to enhance them. So the developers don't want to do that. They want tools that facilitate redundancy and downsizing.

But that doesn’t leave users with a sense of immediate gratification

It leads them to dig their own graves, certainly.