I've still never tried Marimo (I avoid Python when I can), but I definitely do often find myself wishing Pluto would take some ideas from you guys.

Pluto is very focused on educational uses, and tends to be very opinioned in trying to present as little 'configuration' and optionality to users as possible, which I think makes it quite hard to use as an actual tool. It's so close to being something that I really love, but it's just not quite there for me.