SATA was designed for HDDs, and they cap out at around 300 MB/s anyway, so there was never much incentive to further develop the standard.Or is there just no point or incentive to develop the technology further since NMVE M2 became a thing.
I can't help but think we could have had
Sata 4 (1,200 MB/S)
Sata 5 (2,400 MB/S)
Sata 6 (4,800 MB/S)
Sata 7 (9,600 MB/S)