I have enormous respect for mathematicians. They're doing work on the edge, a cross between art and science and music.
Arithmeticians, not so much. They are merely whacking at a calculator, doing repetitive work better done by a computer or someone cheaper.
Many fields have precisely this same division. There's a chasm between the proven, repetitive work that can be farmed out and the cutting edge risky work that might just change everything.
When someone asks you what you do all day and you respond, "I take what comes into this basket, do a standard process to it and then put it in that basket," it sounds a lot like you're doing arithmetic, doesn't it? Far better to have a job where there are equal parts magic and art involved in processing the stuff in that basket.
Sure, it's harder to figure out the values of the Ramsey numbers, particularly R(5,5), than it is to add together 318 numbers, repeatedly. It's harder to create an original tweet than it is to retweet. It's harder to find metaphor than it is to work through a to do list. Hard work, true. But worth it.