All I really need is the ability to create a 2D drawing to scale using simple tools, ideally with tools like offset, fillet, trim. DWG export is a plus, but I’m happy to work in PDF as well.
Inkscape does all of that except DWG and is free.
You can make DXF, though. And there are many free converters out there for SVG to DWG/DXF.
I use Inkscape daily, and have yet to find a design problem I can’t solve with it. This was designed in inkscape:
Scale was extremely important on that design.