But in this future, why will “the most compelling motivations, the clearest explanations, and the most useful maps between intuitions, theorems, and applications” be necessary? Catering to hobbyists?

Most mathematicians don't understand the fields outside of their specialization (at a research level). Your assumption that intuition and applications are limited to hobbyists ignores the possibility of enabling mathematicians to work and collaborate more effectively at the cutting edge of multiple fields.

Very far in the future when AI runs everything, of course math will be a hobby (and it will be great! As a professional programmer I'm happy that I now have a research-level tutor/mentor for my math/physics hobby). In the nearer term, it seems apparent to me that people with stronger mental models of the world are able (without even trying!) to formulate better prompts and get better output from models. i.e. as long as people are asking the questions, they'll do better to have some idea of the nuance within the problem/solution spaces. Math can provide vocabulary to express such nuance.

Mapping theorems to applications is certainly necessary for mathematics to be useful.