A lot of the comments on here are too pessimistic. Deepnote has had the single best jupyter interface for years now - unfortunately locked behind a cloud subscription though. Jupyter itself has been stagnant for far too long, and it's much appreciated there's more options coming online that have a modern level of polish.

Marimo is great, but it's good to have competition in the space (especially when both projects are still owned and maintained by VC backed companies).