A little while ago I posted a reply on this topic in the Visual GDL thread.
GDL is fine. It works, so replacing it seems to make no sense seeing how much of a key part it plays in Archicad.
The issue for me is getting a means of creating GDL objects which works intuitively and easily.
The example I posted was of SketchUp's Dynamic Components, which uses a really simple set of principles to create some pretty complex nd properly parametric components without anything like the GDL learning curve.
I've looked into GDL, and you have to define the geometry point by point in 3d space, which is kind of like AutoLisp. That was fine in the 80s, but it's definitely not now.
I think Graphisoft understand how much of an obstacle GDL is to building a huge community resourced library or parametric content. Look at BIMObject and you will see lots of static components. Sure they have all the parameters, but most of us don't want to browse through 15 different versions of objects all with different specific dimensions to find the one we want. And if we want to change it - we have to do it all over again!
It's awful.
A visual GDL editor would be a great addition. My suggestion would be for a standalone web-based tool, used for building, viewing and modifying GDL objects. It could even output IFC objects, or geometry in other formats. Maybe it could even import geometry and use it for creating Archicad versions of files from other sources.
Once it's accepted that this is a critical feature, there's some interesting discussions to be had over what form the tool should take.
I don't think it needs to be in Archicad. I would go for a standalone separate application, that you can run alongside Archicad. We've seen how Twinmotion's Direct link can work really neatly, why can't we have a web app?
I've seen BImScript and Lena, but these are too complex for most people. Something like the SketchUp approach I think is the way forward.
Archicad 27 UKI | OS X 12.7.1 Monterey