Some tars can be harmful, especially coal-tar and creosote-related materials. Wood tars also need sensible handling because they can irritate skin, smell strongly, and contain complex smoky compounds.
There is no single toxicity answer for all tar. Coal tar is chemically different from pine tar. Roofing tar is different again. Birch tar used in archaeology is not the same as a modern preservative. Any article that says tar is simply safe or simply toxic is oversimplifying the subject.
Coal-tar products are the ones most strongly associated with serious hazard discussions because they can contain polycyclic aromatic hydrocarbons and other compounds of concern. Creosote-related wood preservatives also need careful regulatory and safety treatment. They are not the same as heritage pine tar sold for craft or boat use.
Wood tar is more familiar to traditional craftspeople, but familiar does not mean harmless. It can stain, irritate, smell, and contaminate surfaces. Products intended for outdoor wood are not automatically suitable for skin, animals, food contact, children, interiors, or enclosed spaces.
The practical answer is to identify the tar before judging risk. Source, processing, additives, concentration, and intended use all matter. For tar.fyi/, toxicity should always be explained cautiously, without turning a general information article into medical or chemical safety advice.