...they don't start working until you're fast enough (quite high above the ramp, which is a sensitive area where you really need it) and they stop working once you leave the atmosphere (which is all too soon for an orbital carrier). Why bother with them?
There generally on the bottom stage so they don't reach Anything close to orbit. But what there really useful for is dampening rotations which is hard to fix with a thrust vectoring system.
Anyway, almost all modern rockets don't use fins. They steer using thrust vectoring and attitude control thrusters.