I’m curious: what are some problems where awk was (presumably) a reasonable choice at first but then the implementation grew into a behemoth? Did the solution need to grow as the problem grew? Or was awk just the wrong choice from the beginning?

One case I saw it used was for processing genomics data. It was kinda ok at first but when we needed to add a new sequencing type it was laborious.

Personally I don’t think awk is a good choice for anything beyond one liners and personal scripts. Here it was fine because it was (initially) some write-once academic code that needed to not be insanely slow.