Basically no support for CAD software. I started out on FreeCAD back in 2016 then switched to Fusion360 a few years later. I gave FreeCAD another go a little after it hit 1.0 but it still feels so clunky in comparison.
Even though I share most of my designs, I'm not interested in the free version of OnShape where there isn't a choice in the matter.
I'm no professional so I could probably make due with FreeCAD but I'll be keeping my dual boot since I have the option.