I don't think there is a problem per-se, it's just that G-code tends to be rather static so if you're doing things like nesting and engraving of variable text going through and extra G-code conversion step can get a bit tedious.
I'm old school enough that I can program G-codes by hand (and by heart), compared to normal programming it is super simple, you can pick it up in an afternoon. But for complex graphical work the automatic conversion to G-code from a drawing tool is a real time saver. CAD/CAM software tends to export in some 2D format for laser cutting, usually either a 2D DXF file or SVG. You then convert on the fly to G-code in the laser driver software.
I'm old school enough that I can program G-codes by hand (and by heart), compared to normal programming it is super simple, you can pick it up in an afternoon. But for complex graphical work the automatic conversion to G-code from a drawing tool is a real time saver. CAD/CAM software tends to export in some 2D format for laser cutting, usually either a 2D DXF file or SVG. You then convert on the fly to G-code in the laser driver software.