It looked simple: 20 years ago I experimented with homemade friction drill bits as the commercial ones were way too expensive.
We ground similar shaped tungsten bits (ø5 and ø7) - neither quick nor easy. We needed a rigid drill press and a strong worker. Result: Very little material flow.
It improved when we gave the cone 3 tiny longitudial flats - i.e. a polygon cross section. The (absurd) final solution was to drill a ø3 pilot hole and then widen it with friction drilling (we needed the extra 'thickness' to cut threads). Cut! Avoid threads in sheet metal.