SketchUp 8 was the easiest software for me to learn, and it just clicks with me. I really wanted to learn FreeCAD, but there's something about the way it works that I just can't get along with, so I keep going back to SketchUp.
Later, I tried all the alternatives: Onshape, Fusion, Tinkercad, and the new SolidCraft, but SketchUp still feels so simple and intuitive to me.
I've had better luck with OpenSCAD for simple things, and I still need to try it out with LLMs. That's on my TODO list!
It's also weirdly good at taking an existing STL file of a functional print and writing some python to modify it.
One example was a badge holder that I liked the design of, but only held 2 badges. I wanted 3, plus a slot on the back for a key. Gave it measurements of the key, it grafted a key slot on the back, and added the third badge slot. In typical 3D printing fashion, of course I had to print like 5 iterations of the thing until the sizing of everything actually worked.