Comment by jwagenet

The problem with FreeCAD and every other free/open source MCAD project of note is the Open Cascade kernel they are built on. While Open Cascade is fairly mature, it has dealbreaker issues in a few key areas: fillets cannot consume connected faces and may fail for a number of other reasons, cylindrical and spherical faces require seams which often cause issues with boolean operations, and shapes like helixes are also often troublesome.