Homeassistant already has tons of integration into power providers and easily let's you pipe in local data if you have it. In addition - can it be a product if anyone can just type what this guy did into an LLM? What's your moat if anyone can just replicate it?
It doesn't have to be a durable.moat for it to be a product that makes the author money, just right place right time. If it's gonna cost me a bunch of time and effort and tokens, and the cost of the product is lower than the time and effort and tokens, then I'd rather pay for the product.
Right now we're in $1 Uber ride territory. That $20/month OpenAI/Anthropic plan isn't going to last forever. If it's going to cost me $100 in tokens to replicate the product, $20 is a cheap no brainer purchase m