I used to write web apps in C++, so I totally understand not caring if it gets the job done.

I guess the difference where I draw the line is that LLMs are inherently random I/O so you have to treat them like UI, or the network, where you really have no idea what garbage is gonna come in and you have to be defensive if you're going to build something complex -- otherwise, you as a programmer will not be able to understand or trust it and you will get hit by Murphy's law when you take off your blinders. (if it's simple or a prototype nobody is counting on, obviously none of this matters)

To me insisting that stochastic inputs be handled in a framework that provides strong typing guarantees is not too different from insisting your untrusted sandbox be written in a memory safe language.

What does static type systems provide you with that, say, using structured input / output using pydantic doesn’t?

I just don’t follow your logic of “LLMs are inherently random IO” (ok, I can somehow get behind that, but structured output is a thing) -> “you have to treat them like UI / network” (ok, yes, it’s untrusted) -> static typing solves everything (how exactly?)

This just seems like another “static typing is better than dynamic typing” debate which really doesn’t have a lot to do with LLMs.