No confusion here.
My wifi is as fast as my gigabit LAN.
But you keep thinking your way.
Your confusion was thinking this is somehow related to cell mobile systems.
5G uses a much faster technique and can support very short packets (very short preambles and overhead) saving energy for battery operated devices. WiFi cannot do that. Bluetooth was a flop in the HA area, with it's poor distances and very slow speeds.
5G supports speeds up to Terabits per second, for the future wants and needs. Dozens of mobile service providers share the same bandwidths to thousands of mobile phones and still beat WiFi speeds on each cell phone.
We already have WiFi that spans large areas in many cities and they are not shared with your LAN WiFi. 5G can do it much better for a HA installation. It could obsolete all existing RF style HA protocols and be as reliable as any wired network.
We still have 10Mbps Ethernet and 55Mbps WiFi hanging around too.
OTOH, 3G mobile has been removed from the cell towers here, and that didn't take more than a few years after 5G was launched. When the young adult market is convinced it wants something, there is no limit to the money available and old technology, more than a year old, gets tossed quickly.
Watch for 5G, or likely a similar protocol with a new name, on future routers. I have a tri-band router now already capable of 4Gbps using the 5GHz band shared with aviation radar systems. Of course it will take years for the old devices to fade away.