The issues with manufacturers changing the deal after a while are annoying and very real. That said, if you focus more on how to build geometry with the tool, and less on "click there, then there", you will be able to transfer your skills to another tool if needed. It's still annoying, but at least you're not "stuck" if they bait and switch you.
All that said, if you plan to do more than 3D printing, Fusion is still a good option. The built in CAM is pretty good and quite flexible. So if you ever want to do CNC, you can. It can also output gcode for laser, plasma, 5-axis, electronics, etc..
If your plan doesn't include the extras, absolutely give the open source options a go. Or even just to try it for learning the basics. You might decide you hate CAD. And FreeCAD is a good program that might well do everything you need.