Over reliance on LLMs: Has anyone else run into the problem where LLM costs look fine during MVP, then quietly become painful as usage grows? - I will not promote

We keep seeing startups route even simple backend and application logic through frontier models. This includes extracting fields, classifying support tickets, normalizing messy records, matching entities, converting text into JSON, scoring categories, summarizing highly templated notes, and deciding the next workflow step. To my surprise, I recently discovered there is a well regarded (technical prowess) unicorn startup whose engineering team also fell into this tarpit. Early on, this makes complete sense.