Yeaa. The YouTube video where andrej karpathi setup chatgpt from the scratch. Lookworthy.
It's just an algo. The work and money is in the optimisation of all parts around it. Mostly the text classification, storage and of course computing.
My take is that default styling is already bloated enough. Every-time I need to start out a new project, the first thing I do os to reset default styles.
Also, we already have a situation where different browsers have different defaults leading to an overall worse UX of the web.
credit karma used to be good like most other services that are popular... I think that they were some of the first ones to give you your credit rating for free and tell you why it moved, etc...