I've not yet found a program that is worth the learning curve investment, at least since MacDraw back in the 80's, which was perfect and intuitive for furniture design. I find programs like Illustrator and Photoshop to be trivial in comparison to the many CAD programs I've tried. I put a solid month in on Sketchup with a 3 day class, private tutorials, and lots of practice. It was a disaster, there was still always some well hidden unfinished object or surface that screwed things up-- the program seemed buggy as heck. I gave up.
When I need to, I use either Fusion 360 (the free version) to make drawings for 3D printing, or EasyDraw for 2D drawings. If I just need a picture rather than a "measured drawring" I use Illustrator, or even Powerpoint.
I don't find 3D drawings to be particularly useful for design purposes, I actually can better envision the object by looking at 2D front, site, and top elevations than at a 3D perspective picture. As my wife frequently reminds me, I'm weird. When I'm designing nothing so far beats paper and pencil-- it's only gotten worse as I've started making furniture with more curves and fewer straight lines.