[HarHarVeryFunny]

I'd guess a bit of both, perhaps more on the data side. One could also flip the question and ask how is this new Anthropic model able to beat GPT-4 in some benchmarks?

As far as data, OpenAI haven't just scraped/bought existing data, they have also on a fairly large scale (hundreds of contractors) had custom datasets created, which is another area they may have a head start unless others can find different ways around this (e.g. synthetic data, or filtering for data quality).

Altman has previously said (on Lex's podcast I think) that OpenAI (paraphrasing) is all about results and have used some ad-hoc approaches to achieve that, without hinting at what those might be. But, given how fast others like Anthropic and Google are catching up I'd assume each has their own bag of tricks too, whether that comes down to data and training or architectural tweaks.