I do think post training smaller open source models for very narrow tasks is largely overlooked and there'll be lots of value there if one puts in the effort. However, in a lot of cases we're just compeleting a circle back to deterministic behavior at 1000x the memory/compute requirements just to avoid writing regex.

I agree with you, there's a way to use them responsibly like your router anology, I just think most aren't doing this correctly and its a slippery slope. I'll contend that you probably have used them responsibly in your example.