Isn’t this like a pivot table, that many advanced BI solutions (that have a modeler inside) already have ?

It is and it isn't.

It looks like a polished thing that from a UX perspective sits between a spreadsheet and PowerBI

It let's any user with DB access build reports pretty close to how you'd edit a spreadsheet and without having to build pipelines in PowerBI and setup ingestion etc, etc.

The closest thing I've seen here is the old Tableu Desktop, but this one is more focused on tables than figures.

Not really. Ultorg can do anything SQL (DML) can do, and pivot tables can't do any of that. Ultorg also does pivot tables: https://www.ultorg.com/docs/present/crosstabs/