High level multiphysics, RF, and CAD tools and simulators. Autodesk, Ansys etc. still dominate the field. The state of tools like OpenFoam is like the early days of Gimp and KiCad; theoretically possible to use but only if your background is in software engineering and/or if you are really, really poor and desperate e.g. a grad student on a tight budget. If you look at software like open source FTDT sims, almost all requires specifying layouts, project settings, and designs in ridiculously long config files that would put JS build tools to shame. If you are lucky, you might be able to design your model using a proper GUI e.g. Gmsh. If you are not, be prepared to start drawing out your model with a text editor, point by point. Imagine creating SVGs by hand, that's how ludicrous it is. Most of the "open source" stuff are grad projects, more of an exercise in show and tell than anything serious. Sure it is perfectly possible to specific the cross section of an airplane wing by hand. By the time you are done with that your colleagues using proper GUI tools have already ran their simulation and published three papers.
For those who are interested, one promising project is SU2: