[jcla1]

This sounds like an organisational nightmare to be honest. You'd be going through the pile of exams multiple times (at least twice) and what do you do if there are multiple mistakes that are common in a single exam question?

Also: if you're sorting into "mistakes piles" for single exercises, how can you parallelise marking of separate and independent questions?

[cvwright]

Teach at a broke public university, and you never have to juggle huge teams of TAs.

[kkylin]

Even at top-notch universities (public or private), when I talk to retired faculty, grading almost always comes up as a reason they don't want to teach anymore.

[Edit: not disagreeing with your point.]

[jcla1]

I do (I'm a mathematican). We are usually between 4 and 10 people marking an exam with anywhere between 50 and 600 participants.

[kkylin]

Online tools like Gradescope make this a little less painful (but still painful), but sometimes it's what's needed, especially on problems that are a little open-ended.