Honestly, OpenSCAD has a great UI - it's everything else that sucks about it. OpenSCAD's core advantage is that if you can code, then it is so damn simple; cube sphere cylinder variables modules rotate translate (and if you want to be really fancy: hull union intersect difference), that's all you need for 99% of projects and it fights onto a half-page cheatsheet.

The problem with OpenSCAD is that it's fundamentally really dumb; it doesn't have constraints, you usually just create shapes additively but then you have awful Z-fighting because the engine sucks, and the solution is "just barf epsilons everywhere lol" (which is pure cope - that's not a solution, that's an awkward workaround that requires a bunch of pointless busywork (and more importantly, forces you to figure out stuff about your model that you legitimately don't care about) because the engine is incapable).

I would love to see a successor to OpenSCAD that keeps its IDE-style interface (and no, that doesn't mean using pycharm - the beauty of OpenSCAD is that you have a minimal functional DSL and the GUI is built around the DSL and its use-case) but finds an elegant method of integrating constraints, basically anything to do with curves, that sort of stuff.