The primary way to increase reliability is to automate. Instead of humans producing some output manually, humans producing machines which produce that output.

I've seen a disturbing trend where a process that could've been a script or a requirement that could've been enforced deterministically is in fact "automated" through a set of instructions for an LLM.

Sure, when that is possible. However, there are lots of processes we don't know how to automate in a deterministic way. Hence the vast amount of investment in building organisations of people with mechanism to make peoples output more reliable through structure, reviews, and so on.

Large parts of human civilization rests on our ability to make something unreliable less unreliable through organisational structure and processes.