It's common for the next generation of cell service to be in development a decade or more before real word testing begins. And of course there will be some confusion for folks seeing references to "6G" (6 GHz) WiFi versus "6G" (6th Generation) cell service.
6G could be the next big mobile networking standard after 5G. Here's what 6G might look like and how it will be different from 5G.
www.lifewire.com
Yes, that has been true, but the 6G standard is much further along (something like how 6K for TV's--I think it was 6K--was not far at all from being ready, but the investment in 4K (UHD) had already been made, so the TV makers weren't interested, YET).
6G could be achieved in about the same time as reaching true 4G specs (and LTE Advanced specs), but it always boils down to investment by the wireless companies, so the economics won't make sense to set up a 6G network in the USA for some years even though it can be
theoretically done a in a few years, but the reality of new bandwidth or converting bandwidth and capable phones is the real barrier, while there are mobile phone chips that can meet the true 4G specs.
In fact, the plan for the wireless companies it to convert 3G band to the 4G/LTE network, so 4G/LTE (with perhaps reaching its true top specifications that would result in a 5G-like experience). And yes, the confusion of all the numbers of G and WiFi 6 and you name it is an excellent point that you brought up. What a mess letters and numbers.