Our positioning (e.g. principal use cases, target verticals, target persona) and timing were totally wrong. We tried to run top-down sales against relatively important data (e.g. sales forecasts). People often expressed an attitudinal interest in the product, but it was very hard to motivate people actually to use the product seriously. Category creation and behavior change are really hard.
If I were trying to sell an LLM data cleaning product now, I'd focus on more technical buyers, someone more like a data engineer than a strong spreadsheet worker. And I'd try to drive bottoms-up, low ACV adoption first.
Doing the post-mortem justice would probably require a long blog post.