I've found for most substantial proofs I've been exposed to I understood the author's justification of how they found the proof. That doesn't mean I would have been able to come up with that step on my own, but once it was done I understood why they took it. If you get sufficiently far into the esoteric weeds of either analysis or algebra, the justifications won't be understood outside that field. But they don't have to be.

Theorem provers starting from basic axioms are often looking for things that aren't in the esoteric weeds of a specific subfield as it often takes too long for them to generate a suitable set of theorems that establish those fields.