'Frugal 5G' bring broadband Internet to half world's population?
Mobile can bring Internet, it's not economic to provide Broadband, you'd need x10 to x20 higher density of base-stations. That's x10 to x20 more CAPEX and running costs for no extra customers. It's then actually little difference if 3G, 4G or 5G used. Or WiFi as unless the cell sizes are reduced to typical femto cell / wifi sizes you don't have the capacity.
Even bonded IP only version GSM can do better than average DSL broadband with that density of base-stations.
Fibre is the only economic way for fast broadband, and now as cheap as copper. The 1Gbps Fibre to Home (FTTH / FTTP) actually is cheaper and less power consumption than Mobile that gives an minimum 1Mbps at peak time at all locations.