The scale. How many tools do you know that can query the content of all arxiv papers.

It's just marketing.

It is not a protected term, so anything is state-of-the-art if you want it to be.

For example, Gemma models at the moment of release were performing worse their competition, but still, it is "state-of-the-art". It does not mean it's a bad product at all (Gemma is actually good), but the claims are very free.

Juicero was state-of-the-art on release too, though hands were better, etc.

First, so best in this?

The tool is state of the art, the sources are historical.