CSI-2 is a high speed differential interface with controlled-impedance pairs.
50
single-ended, 100
differential, length matched.
You’ve typically got two data lanes, a clock lane, so that’s six wires for the high speed pairs. Maybe some extra coplanar grounds. Plus 3.3V and ground, and two wires for I2C control, but those four are not so high speed.
Personally I think the FFC sucks, and something like a USB3 or SATA connector might work nicely.