I think you're really out of touch with what is going on in the WISP space.
See the following product as an example:
14x14 beam-steering Massive Multi-User MIMO. This is able to talk, in the same channel, at the same time, to up to 7 endpoints using both vertical and horizontal polarities at the same time. Total throughput per 40Mhz channel: 1.2Gb/s per AP.
Because of the TDMA synchronization, you can actually hang two of these on the same tower front to back using the same channel. So 2.4Gb/s per Frequency. And there are dozens of channels available at this point.