FreeCAD on desktop is much the same in my experience. If LLMs were mainstream a few years ago I would have assumed the UI was 100% AI generated with zero human input besides a oneshot prompt.
If Solidworks and Onshape were born after the birth of LLMs, they'd probably be glitchy as hell.
When was the last time that you used FreeCAD? Even 18 months ago, I would agree with you that it was a buggy mess, but I tried it a few weeks ago and it was super stable. The UI is still a little confusing, but that just comes with the domain, since AutoCAD and Fusion 360 aren't much better.