I don't get your post. On the one hand you say that you need to go to FR2, due to higher throughput requirements. On the other hand you point out beam forming, MIMO etc. as the real difference between 4G and 4G. But that's exactly the technology used to get higher throughput. You don't need more bandwidth necessarily to get higher throughput, there is a D term in the Shannon formula, thus you can go to several spatial paths to increase throughput.

I doubt we will see _real_ THz comms in 6G, maybe we go up to a few 100s of GHz, but not THz (I know many in the industry use THz to mean anything from ~50GHz, but that's just marketing rubbish).