Freecad can replace fusion for basic cad work. It does have some stability issues but overall it is perfectly usable. (Just don't do anything with threads)

I moved from Creo to FreeCAD. For a free software, FreeCAD is insanely good. But it's clear that it is an enthusiast project with focus on functionality rather than UX and UI, allthough they are starting to improve on that too. It's also clear that all industry grade software providers must headscout some of the smartest and most talented mathematicians and software engineers, which open source can simply not afford.

I took for granted how performant and flexible Creo is with things like chamfers and patterns. FreeCAD struggles in that regard hard, to the point where those steps have to be the last things in your workflow, otherwise the entire model lags out or even crashes.

Also, compared to FreeCAD, the actual constriction feature management seems like magic in Creo, it keeps way better track of the naming and numbering of references and minor changes to earlier elements transfer seamlessly to all newer ones. Meanwhile in FreeCAD adding even a single borehole into a surface retroactively (which shouldn't influence anything else) completely breaks the model and all surfaces need to be reassigned by hand to all upstream elements.

Threads are another issue. I know cosmetic threads are super easy to do in Fusion, and are especially important for 3D printing. The most effective way to get cosmetic threads in FreeCAD is to use a plugin that gives you parametric rods, nuts and cutting tools and you just use a boolean operation to basically cut a thread into geometry. It works perfectly, but is simply really weird and unusual.

In general FreeCAD can do anything an industry standard CAD Programm can do, it will only take you 10 times longer and is 5 times more complicated. Sometimes the same operation will work on one edge, but not it's exact copy. Sometimes a feature works on the selection, sometimes you get a seperate selection window for the feature. It's clear that a lot of implementation happens without proper communication inside the FreeCAD team and therefore lacks in consistency.

But it seems that this year is going to be the year of FreeCAD as they significantly ramped up development and there are almost monthly improvements. They also make effort to unify features and improve consistency across board.

Your mentality needs to be that FreeCAD models are clunky and fragile and you essentially have to already know exactly what you want to design before even starting. It's not a great tool for creative technical experimentation, for now at least.