Especially with additive manufacturing, SDF's are far superior but still not widely used (but I predict this will change very soon). As others have said, many operations are much easier when working with SDF's, but specifically for AM, there are many operations like lightweighting that are extremely difficult to do "correctly" when using normal meshes. For simulations as well, an SDF makes things like voxelization, random walks, and basically everything else that is related to the topology of a part much easier.
Check out the company/product nTopology. It's IMO the future for engineering modelling and CAD for AM.
I used to work for an AM company and was essentially the internal evangelist that complained about STL's and "traditional" CAD formats that are proprietary or just outright a PITA to work with (I'm looking at you, STEP...)