There are a number of reasons to choose Observable’s plot over plotly, but to address your point, there is no lock-in here with using plot for the view - you can seemingly use any JS library, including plotly, vega, D3, etc., so I don’t think that’s a huge issue.

I agree with your point regarding convincing other scientists to use JavaScript - that was the biggest point of failure for Observable notebook adoption that I saw. (As an anecdote, rather than adopt Observable, my science team @bigtech decided to write a Jupyter -> interactive static site transpiler, so the scientists could continue their work in python). Observable 2.0 seems built on recognizing that friction, and making it so that the it’s much easier for non-js users to collaborate. But the npm dependency will still scare many data folks away.

To anyone from observable reading: I think getting mass adoption involves making this as seamless for python users as possible. (E.g. something similar to marimo notebooks or evidence). Also: great work!