It's actually very logical.
PCIe 3.0 is barely used over PCIe 2.0, thus, PCIe 4.0 will be even less used over PCIe 3.0.
Samsung is now talking about three major improvements they bring over earlier SSDs in addition to the raw performance increases enabled by PCIe 4.0.
Given this, how will SSD market look in few years? Sorry I am not smart enough to follow your logic.....
Now you see why I would like PCIe 4 to plug these into?