I've been using it to build things that don't exist in the market (or GitHub). Either where the product just doesn't exist, or existing products do not fully meet my requirements.
For example I got a smart cat litter box and wanted to pair it to Home Assistant. There's an existing integration for the manufacturer, but it seems that although my box has the same model number, it's a different revision with completely different data point mappings - so the existing integration doesn't work. I pointed AI at it, and it figured it out, and it works.
Could I have done it? Sure, if I'd spent an entire afternoon doing it. I don't care that much about my cat litter box though.