Isn’t that other data vital?
What use is knowing that my British Gas direct debit is £100 but the average person is paying Npower £90 if you don’t know what my actual tariff details are, including things like penalties for leaving early, whether I use economy 7, if I’m eligible for social tariffss etc.
As well as habits. Like how often I use gas to cook. Sure from payments if someone is buying loads of takeaways you could assume they aren’t cooking often, but that’s an individual’s spending, the rest of the household might be different.
I think you could definitely say “hey, you’re spending more than others with similar spending habits it might be worth looking into switching”. But without much more data it seems a stretch to be able to recommend a better deal.