You would not enjoy being freeze-dried and neither do microbes. The process of freeze-drying damages the vast majority of the microbes being processed. Only 1/10th or even 1/100th for the microbes you start with will survive the process in a condition from which they may possibly be brought back to life.

The process of reanimating a freeze-dried culture takes another heavy toll with again only 1/10th to 1/100th of the microbes that may have been able to survive actually finishing the process in a condition where they can metabolize and reproduce.

The above means that only a tiny fraction, 1/100th to 1/10,000th, of the microbes that enter the freeze-drying process will ever wake up and get to work trying to be a probiotic. Further, this process takes time meaning that the tiny fraction of microbes that make it through the gruelling process can only benefit that lower part of the gut that they find themselves in once they get to work.